Saturday, December 24, 2016

John Welsford's Mollyhawk & A Texas 200

John Welsford’s Mollyhawk is 15% longer than his Seagull, but the widths and heights are the same. Though flat bottomed, she is narrow on the bottom, with flaring sides reminiscent of New England dories. With plenty of rocker, she makes a fine row boat. Plans are available on Duckworks.

Specifications:

  • Length: 17' 2" (5.3 m)
  • Beam: 49" (1226 mm)
  • Weight: 93 pounds (42 kg)
  • Water Line Length: 15' 11" (4.8 m)
  • Water Line Width: 38" (953 mm)
  • WLL/WLW Ratio: 5.1:1
  • Hull Speed: 5.3 knots, 9.8 kph, 6.1 mph


Andrew Linn in a Mollyhawk 


Rick Laudervale and Andrew Linn Rowing another Mollyhawk

Andrew Linn:

“She FLIES on the water - just slips along like a queen. Both Rick [Laudervale] and I weigh over 200lbs and you can see how nicely she trims [photo above]. What really surprised me was her maneuverability. The keel is just deep enough to get her to track nicely but she can turn in her own length.”


Conversion to an Oar Cruiser:

  • Add two bulkheads with large water-proof hatches to create a cockpit 7' (2134 mm) long centered in the hull.
  • Eliminate the seats.
  • Add a fore deck (SOF or 4 mm plywood) extending from the bow to 1' (305 mm) aft of the forward bulkhead.
  • Add an after deck similarly extending from the transom to 1' forward of the after bulkhead.
  • This will create 2 water-proof compartments for storage and emergency flotation, as well as a 7' (2134mm) sleeping/rowing cockpit with a 5' (1524 mm) opening.
  • Add cross-slatted floor boards spanning the width of the bottom and bulkhead to bulkhead, sitting on top of the three frames.
  • Add a rowing seat and foot braces that lock into the floor boards.
  • Add a shelter to be used for sleeping.

Commentary from John Welsford:

"Mollyhawk! She looks as simple a boat as its possible to be, flat bottom, straight sides, transom, some seats and oarlocks. But they perform a lot better than many flat-bottomed boats, and they do that because there was a heap of study, several tow test models, and two full sized prototypes before the shape was finalized." [dwforum, Nov 27, 2016]

“Recreational or sports rowing boats are often pretty easily upset, the narrow waterline beam making them very tender. In this boat, though, the bottom is wide enough to allow one to stand up within the boat (carefully), stability which, although it does knock a little off her performance, makes her a much more versatile craft and only about three minutes in the hour slower than her more sophisticated sister Joansa [featured in this blog post]." 
"Rowing a boat like this is nothing like most boaties have ever experienced, they move incredibly easily using very little energy, and once the technique of [establishing a rhythm in the oar stroke] has been mastered, it can be rowed for hours on end at a speed that would surprise many sailors. A good recreational rowing boat, unlike the delicate “toothpick” that the competitive rowers use, can cope with even quite extreme weather conditions, and with an experienced rower in charge will ride over seas that would put much larger boats at risk." 
"Mollyhawk! She looks as simple a boat as its possible to be, flat bottom, straight sides, transom, some seats and oarlocks. But they perform a lot better than many flat bottomed boats, and they do that because there was a heap of study, several tow test models, and two full sized prototypes before the shape was finalized." [dwforum Nov 27, 2016]

A Texas 20 Odyssey

Rob Fisher and his son rowed the 2016 Texas 200 in a Mollyhawk… following is Rob's description: 

Rowing Tips for the Texas 200

By: Rob Fisher 
"Now that the 2016 Texas 200 is over, my son and I have recovered, I wanted to capture some thoughts and suggestions for future rowers. Our significant effort for training, planning, and rowing allowed us to be 1 of 18 boats to arrive at all camps in 2016, rowing a total of 224.6 miles over 6 days and 10+ hours each day of continuous rowing. I hope these thoughts will help future masochists.

1. Boat Selection

"What boat to row, selection is one of many trade-offs. You will have to deal with
very diverse weather, wind and water conditions. First you need to be able to
carry considerable cargo loads for all your gear and provisions. Just consider the
weight of the water we carried this year was 216 pounds. We experienced high
winds in excess of 20 mph from different directions, high waves and some
current. We built the Welsford Mollyhawk with two rowing stations. Weighed in
at ~170 pounds for boat and rowing stations. LOA is just over 18 feet, 4 foot
beam. 
"Freeboard is needed for the high waves and cargo capacity, but it creates a lot of
windage. There were times when we clocked in at 3.5-4 mph without rowing
going dead down wind. The trouble was that it wasn’t in the direction we wanted
to go. Despite our amount of freeboard we still took waves over the side, over
the stern and one over the bow. 
"Get an estimation of the weight you think you will carry. The single biggest load
was our water. We carried 26 gallons at the start. We carried it in 1 gallon jugs
which was great. It allowed us to move it around the boat to balance it
depending on the wind and wave conditions. We were consuming 4 gallons
each day for 2 people so we kept the empties in case we needed extra ballast
later in the week. The first days we had the highest waves and the extra ballast
from the water made our boat really stable. 
"Sliding seat or fixed seat is a personal choice. We have always rowed sliding
seat. We prefer it as it allows you to use your leg muscles when rowing.
Through our training, [we found] if we rowed with the sliding seat compared to no sliding, it increased our speed by ~50%. 
"Seat comfort (or lack of it) is extremely important and we underestimated this one. We used carbon fiber molded seats with thin padding. They felt fine for the first 20 or so miles for a couple days, but nothing feels good after sitting 11 hours every day for 6 days. By the end of the trip our back sides were suffering. 
"One thing we didn’t have was a rudder. Traditionally in a row boat you don’t
really need one. Just take an extra pull on one side or the other to change
course. We found with the wind and waves it took considerable effort to keep the
boat on course. On day 2 we had a side wind of 20+ mph and there were times
we rowed for miles with the starboard oar only to go where we wanted.

2. Training 

"I can’t emphasize this enough. What does it take to go from rowing in a racing
shell for a couple hours a week, to rowing 10+ hours a day, for 6 consecutive
days in a boat fully loaded with gear? One can potentially row and push yourself
for a day or two, but doing it 6 days in a row requires some base level of
conditioning unless you want to suffer a lot. 
"Our training started in January, 5 months before the event. We were either
rowing on the water or on a rowing machine 6 days a week. During the week we
rowed one hour each day, then on the weekends we extended the distance using
a modified marathon training plan[see chart below]. During the long training days, we were able to test the boat, food, hydration, different weather and build physical conditioning.
 
"In January we rowed 7 miles one Sunday and it took us 3 days to recover. At
that point we wondered how we could row 40+ miles each day for a week. The
key for us was having a written plan and sticking to it, never give up. 
"Basic rule, build up miles for a couple weeks, then drop back to rest and build some more. At the end do a gradual taper to rest before the event. 
"We developed a rowing strategy so that we could stay hydrated and fueled. We
would double row for 25 minutes, then one person would take a 5 minute break
to eat and drink while the other person single rowed. Then switch and start over
again. We did this non stop for 10+ hrs each day. We also took one long break
just over half way through the day. This allowed for more stretching and rest.
 

Rob Fisher's (& son) Training Regime for Rowing the Texas 200


3. Sun Protection
 

"One constant for South Texas is the heat and sun. I can’t emphasize enough
how un-relenting it is. There are two strategies for sun protection. Use tons and
tons of sunscreen and hope you don’t miss something, or cover everything up.
We chose to cover up since we would be sweating a lot. Lightweight clothing
takes some of the heat load off your body. We didn’t want to get sunscreen all
over our hands and oars.

4. Hand and Physical Health

"If you have rowed at all, you know that blisters are inevitable. The single most
important thing for a rower is keeping your hands healthy. We used a variation of
techniques during the trip. During all our training we found the single biggest
factor in hand health was keeping our hands as dry as possible. Wet hands turn
soft, soft hands get hot spots, hot spots become blisters. 
"Our routine was to start out in the morning with bare hands for the first 3-4 hours of rowing until the sun started getting strong. Then we would tape up our hands and put on gloves. The gloves worked well for sun protection and to some extent they soak up
excess sweat. 
"When we took a break every 25 minutes, the gloves would come off. This allowed for the hands to breath and dry a little. The tape was changed out a couple times a day. The tape helps protect from blisters and gives your fingers some extra support. Following that strategy, we had very few blisters.
"The ones we did get weren’t debilitating and could be managed. We also took
hand sanitizer for cleaning our hands and oar handles. If you have ruptured
blisters, you don’t want an infection.

5. Hydration and Nutrition 

"Rowing non stop all day long takes a lot of food and water. We consumed 2
gallons of water each day per person for food and drinking. We figured we were
burning something like 400-500 calories each hour of rowing. We started the day
with a hot serving of oatmeal. We joked that it should be an Olympic event to eat
one serving, but we never went hungry. 
"One serving oatmeal:
   1 cup oats
   1 T chia seeds
   ½ cup dried fruit
   ¼ cup sunflower seeds
   ¼ cup pumpkin seeds
   ¼ tsp cinnamon
   1 T brown sugar
   2 cup water for thick, more is better 
"It was nice to have a hot meal for breakfast. For the remainder of the day we
had snack food (no lunch). We tried a lot of different things for snacks. Keep in
mind it’s hot in Texas. Anything with chocolate becomes a mess. This includes
chewy granola bars which melt in the heat. Some different ideas we tried;
  
    • Various granola bars,
    • peanut butter filled pretzel bites,
    • various different trail mix,
    • various nut mix,
    • jerky,
    • dried fruit,
    • peanut butter crackers,
    • and cheese crackers.
"We actually had to force ourselves to eat. Since you are exercising a lot you
don’t really get hungry and if you are feeling hungry or tired, it’s too late. Eat
small portions and eat often, even if you don’t feel like it. 
"Before the trip we portioned out snacks into small Ziploc snack bags and then divided out our snacks into gallon Ziploc bags for each day. 
"Doing this helped when we were tired, all we had to do is pull out the food bag in the morning and we were ready to go. No thinking required. We ate on average 350-400 calories each hour. The hardest part was having enough variety. After 5 months of training, we were sick of pretty much every possible snack. For example, rowing 40+ miles over 10+ hours. Eating every 30 minutes comes out to 20+ snacks for the day. After a week, you need a staggering 120 snacks.

6. Navigation

"Rowing offers an additional challenge for navigation since the rower faces the
wrong direction the whole time. There are very few landmarks on the TX200 so
a GPS unit is very helpful. Getting off course or zigzagging around adds a lot of
miles on a 40 mile day.
 
"We used a handheld GPS and had our paper charts as backup. I made a GPS mount that attached to the rigger between the rowers feet so that you could look at it while rowing 
"We made a course with all the way points for each day which was a direct course because we didn’t know any better. We didn’t take into account that the wind shifts during the day by as much as 90 degrees and changes direction as you progress north and east along the route. 
"If we had to do it again we would have pre-planned alternate routes in case the wind changed. This was something we did not expect since we hadn’t done this before." 

 

I thank Rob for taking the time (and candor) to write this.

Tom


Sunday, December 18, 2016

CATCH: Small Boats in Epic Voyages


Dave and Mindy Bolduc, authors and adventurers, have curated an archive of epic voyages in small boats on their "micro-cruising" web site.

The listing is in date order and includes the length and name of the boat, who rowed/sailed/paddled it, a brief description and links to books, articles, photos and/or drawings of the boat. 

For example:
In 1876, Alfred Johnson, sailing/rowing his fully decked “Centennial” became the…
First person to cross the Atlantic solo West to East. This Grand Banks fisherman sailed his gaff-rigged dory from Gloucester, New Brunswick to Albercastle, Pembrokeshire. His boat is now on display in the Cape Ann Historical Society museum in Gloucester, MA.
Alfred Johnson's Centennial Crossing the Atlantic in 1876 

Someplace between untying gift wrappings and feasting on Plum Pudding, you may want to sit back and peruse this list… bury yourself in a true adventure. 

Have a wonderful Christmas Holiday and a safe...healthy 2017!

Best regards,

Tom  

Piloting Part 5, Dealing with Currents


Introduction 


Ignore this post if you ONLY row/paddle in landlocked lakes or reservoirs... there are typically no currents. But if you ever even think about rowing in large lakes (were there can be currents created by extended windy days) rivers, or bays/estuaries that are affected by tides, then continue on.

Tide and Currents


The tides are the result of the gravitational pull of the moon and sun…  the moon’s gravitational pull is about twice that of the sun. The gravitational pull causes a ‘bulge’ in the earth’s waters, about 18 inches (46cm) in mid-ocean. There is a corresponding bulge on the opposite side of the earth, and two ‘hollows’ 90° from the bulges. These bulges and hollows circle the earth about every 24 hours and 50 minutes.
But we don’t typically row in the middle of the ocean… we travel in bays and estuaries connected to the oceans. The bays and estuaries have water levels that attempt to keep up with the bulges and hollows in the oceans. They do keep up, but there are delays while the bays and estuaries fill up with water and then empty to match the bulge/hollow as is passes. This emptying and filling results in tidal currents.
The tidal currents, though caused by the tide, are not necessarily in sync with the tide. This means that the strongest tidal current may not be (and in most cases seldom is) at the half way point of the flooding or ebbing tide.
How do we know how strong the current will be, and when will it occur?

Current Tables


In the United States use NOAA Current Prediction. This is a starting point to access a large array of information.

Using the Currents


The current predictions (how fast and when) are for a single designated point. The current speed can be very different just a short distance away.  What are the factors that affect these differences in predicted speeds/times and how do you use these differences while you are rowing?
    • If a confined waterway (e.g., between two islands) becomes narrow (in width and/or depth of water), the speed of the current increases in proportion to the amount of narrowing. For example, if the waterway narrows 50%, the speed of the current doubles. Another application: Rowing under a bridge… stay equal distance from the two abutments to avoid eddies that occur as the faster current flows around the abutments.

    • The current is slower closer to the shore in a wide bay or estuary because the water is shallower. If you are rowing with the current, stay in the middle or deepest water where the current is stronger. If rowing against the current, stay closer to the shore.

    • The current is stronger on the outside of a bend in a narrow waterway, such as a river… and slower on the inside of the curve. If you are rowing against the current, stay on the inside of a turn… and if rowing with the current, stay on the outside of the turn.

    • A point of land protruding into a waterway often creates a ‘back eddy’ (reverse current) downstream of the point. Heading downstream, row well outside the point to avoid the back eddy. If going against the current, stay inside the point as long as possible to take advantage of the reverse current.

    • A steady wind blowing over a body of water for at least half a day will start a surface current flowing at a speed of about 3% of the wind speed. So an extended 20 knot wind will create a 0.6 knot surface current. Note that the waves created by this wind will increase in size if the tidal current is in the opposite direction.

How Fast is the Current?


One way of determining  current speed is to use ‘speed made good’, which is your actual speed (measured along the shore (i.e., between fixed points) in comparison to your speed in the water.
Example: You are rowing at 3.5 knots and you row past two buoys that are 0.9 miles apart (according to your chart) in 27 minutes. You remember the ‘sixty D street’ formula (60D=ST), solve for S, giving you Speed = 60 x 0.9 / 27, which is 54/27, or 2 knots speed made good. This means the current is 1.5 knots against you (3.5 – 2 = 1.5).  
Example: But if it only took you a little less than 11 minutes to go 0.9 miles (still rowing at 3.5 knots), speed made good would be 60 x 0.9 / 10.8 which is 5 knots speed made good… you’re getting a 1.5 knot boast in speed from the current.
Two issues with this technique: You have to do some math in your head (the real world usually doesn’t come out in nice round numbers like these examples). And second, we have not accounted for wind. We’ll talk more about the effect of wind on rowing in Part 6 of this series. 

 Another way to determine current speed is to measure the current directly:  Current speed (knots) = 0.6 x Feet per Second.

Example: If I’m anchored in my 15 foot boat, and a twig floating in the water takes 5 seconds to go by my boat, the speed of the twig (current in this case) equals 0.6 x 15/5, or a 1.8 knot current. Note that this formula can also be used to measure boat speed…
Example: I’m rowing in Newport Harbor (Rhode Island) and spot a 12 Meter anchored… typically they are 70 feet (21.3m) long. It takes me 10 seconds for me to row by it… my speed is 0.6 x 70 /10 or 4.2 knots.
Example: I’m rowing Barnegat Bay in early morning, no wind, at slack tide. I see a channel marker in my mirror… it takes 3 seconds for me to pass the marker from stem to transom (15 feet)… I’m rowing at 3 knots. (0.6 x 15 / 3 = 3 knots).

 

Crossing a Current


The current table gives the estimated highest speed of the current, typically in the middle or deepest part of the waterway. The current becomes progressively less as you approach the edges of waterway. Because of this variability, it is difficult to predict where you’ll end up when you cross a current.
Let’s say you want to cross a river and end up at point X on the other side. In general terms, there are four ‘strategies’ to get to point X:

    1. Aim for point X (let’s assume X is 85°magnetic from your starting point) and start rowing. You’ll end up an unknown distance downstream (in the current direction) from X. Not a good strategy.

    2. Row upstream close to the edge of the waterway where the current is weakest. When you are ready, head across the waterway at 85°m. The current will take you downstream toward X. Where you’ll end up depends upon how far upstream you went before crossing. But you’ll be better off than using strategy 1.

    3. Use a range (two landmarks in line with X, a LOP). As the current keeps pushing you downstream of the range, change your course upstream. Continue to adjust your course (upstream or downstream) to stay on the LOP. This strategy, combined with strategy 2., has the advantage of landing at X and of minimizing the amount of upstream rowing/paddling that must be done in the strongest current.

    4. Do the following calculation to get the upstream angle (called the Ferry angle) you must apply to your course in order to get to X. Ferry angle = 60 times current speed/rowing speed.
Example: If the azimuth to X is 85°m, current speed is 1.5 knots (at about 180°m) and your rowing speed is 3 knots, then the ferry angle is 60 times 1.5/3, or 30°. This means you should row/paddle on a course of 115°m (85° +30°). And you’ll end up at X… well, not really. Because the current speed is not constant all the way across the waterway. You’ll probably end upstream of X, which is usually not a bad thing. 

 

The Fine Print...


I’m not a professional pilot. I try to be accurate and I check my information, but I’m not perfect. This post is for information purposes and is intended to be only a starting point for learning the skills of piloting. As with any activity with a small boat, there is always the opportunity for ugly surprises. Practice the skills under ideal circumstances and you’ll increase the probability of being able to use the skills during an ugly surprise to keep you and your boat safe.

Sunday, December 11, 2016

The Oxford Wherry 16 as an Oar Cruiser

Colin Angus offers a beautiful rowboat, the Oxford Wherry, that would make a really nice oar cruiser.

Colin Angus's Oxford Wherry

The specifications show that she is fast (note the bow wake in the photo above) and is capable of handling weight you would need for a weekend cruise.

Specifications:

  • Length Overall: 15' 10" (4.9 m)
  • Waterline Length: 15' 7" (4.8 m)
  • Beam: 38" (965 mm)
  • Estimated WLW: 30" (762 mm)
  • Est. WLL/WLW Ratio: 6.2:1
  • Weight: 53 lbs (27 kg)
  • Watertight compartments: 2
  • Depth: 11"
  • Freeboard at 250 lb displacement: 7.5" (191 mm)
  • Freeboard at 600 lb displacement: 5" (127 mm)
  • Block Coefficient: 0.39
  • Prismatic Coefficient: 0.51
  • Sprint speed: 11-12 kph (6.2 knots, 7.2 mph)
  • Cruise Speed: 6-8 kph (3.8 knots, 4.4 mph)
  • Hull Speed: 5.3 knots, 9.8 kph, 6.1 mph
  • Maximum recommended touring load: 500 lbs (225 kg)
  • Maximum recommended short distance load: 600 lbs (270 kg)

Colin Angus Comments:

“The Oxford Wherry combines elements of traditional beauty with modern design and construction to create a vessel that is not just gorgeous, but unbelievably fast and functional.  Its design takes the most positive elements of traditional wherries and Whitehalls – wineglass transom, carvel-like construction, and elegant woodwork - while jettisoning the less-than-ideal attributes such as excessive weight and beam… 
…The hull is shaped for true performance without compromising stability.  The Vee bottom is almost flat in the middle further creating stability (a surprising number of designers create deep Vee in similar style vessels which decreases stability and does nothing for performance).  The Vee increases near the stern and bow to assist in cutting through waves and creating lateral resistance to enhance tracking…”
Interestingly, the Oxford Wherry can also be paddled, useful when exploring narrow creeks and marshes.

Oxford Wherry Paddling...

...or Rowed with Sliding Seat...

...or Rowed Fixed Seat

Converting to an Oar Cruiser:

Following are the modifications that could be done to make it an ‘oar cruiser’ (see definition in right column in this blog), without compromising the hull design. 

  • Add a water-tight bulkhead, with large access hatch, at each end of a 7’ (2.1 m) rowing/sleeping cockpit, eliminating the designed seats, but retaining the frames.
  • Add a cross-planked set of floorboards for the cockpit, spanning the frames, to provide a dry sleeping platform and attachment points for rowing seat and foot rests.
  • Add fore- and aft-decks, as well as narrow side decks, using skin-on-frame, resulting in a cockpit opening of 4’ to 5’ (1.2 m to 1.5 m) long. These decks would partially cover the ends of the sleeping area.
  • Add a 3-inch (76 mm) coaming around the sides of cockpit to increase freeboard as well as a support for short outriggers (to provide oar lock span of 4 feet (1.2 m)).
  • Provide rain protection for sitting headroom and sleeping using some form of shelter.


Colin sells plans for the Oxford Wherry as well as kits. The diagram below shows the panels that are provided in the very complete kit for the boat.

Wood Components in the Kit

Tom Fry has put together a 10 minute time-lapse video of building an Oxford Wherry.

Summary-Pros:

  • Proven design by an accomplished designer who has taken his boats on epic voyages.
  • Light weight enables car-topping.
  • Decking, coaming and light weight provide seaworthiness for inland waters.
  • High WLL:WLW ratio (6.2:1) and light weight enable fast cruising speed.

 

Summary-Cons:

  • Narrow WLW (30", 762 mm) and low freeboard (7.5", 191 mm) limits displacement.




Sunday, December 4, 2016

Piloting Part 4, Distance Off


In Part 3 we discussed getting the answer to “Where am I?” and introduced a couple of ways to measure distance off… distance from a visible object that is also on the chart. In this post, we’ll show additional techniques to measure distance off.

More Preparation


 In the post on "Preparation", we suggested you print charts of the area you intend to cruise in. There is some additional preparation of those charts which can be very helpful when piloting the area.

  • Mark a scale on the chart for distance in miles or kilometers. For example, if the chart is scaled 1 inch to the mile, draw a line  4 inches long, with tick marks at 0, 1, 2 and 3 miles, then divide the last inch into eighth inches. Then it will be easy to measure distance on the chart.

  • Annotate major land marks such as water towers, bridges, light houses with heights, widths, colors, etc. If you do a Google search for the object, you can often find the required information. For example, when I did a search for Mantoloking Bridge , I found the center span vertical clearance is 30 feet and the horizontal opening is 80 feet. Published nautical charts typically provide this information.

  • Pre-measure and mark on the chart distances between points that will be obvious from the water. For example, the distance between two jetties protecting an inlet... distance between two small islands... distance between two shorelines that mark the edges of a narrow channel. You'll see in the discussion below how having these measures at hand will help you.

Using Object Size to Estimate Distance Off


We can estimate distance by noting what we can see at various distances. For example…

  • At 5 miles (8 km), we can see houses (but no detail), ships, water towers, light houses 

  • At 2 miles (3.2 km), we can see large trees and windows in the houses 

  • At 1 mile (1.6 km), we can see big branches in trees, large buoys

  • At 1/2 mile (0.8 km), we can see people as dots or sticks, small buoys 

  • At 1/4 mile (0.4 km), we see people's arms & legs, detail on boats, such as an outboard 

  • And at 1/8 mile (0.2 km), we can see faces, registration numbers. 

Using Small Triangle to Find Distance Off 


Doing this is illustrated in the diagram below:


Let's make this easier by simplifying the 'mathematics' we have to do.

How to Create the 'Small Triangle' Using a Kamal


To make the mathematics easier, we need to make a 'kamal', an Arabic device that was originally used to measure the altitude of the North Star so that sailors were able to sail east and west (along a given latitude) between Africa and India out of sight of land for weeks at a time.

Here's one way to make a kamal: Use a 6" (15cm) plastic ruler and at least a meter (40+ inches) of heavy (durable) string. Tie one end of the string to a (carefully) drilled hole in the center of the ruler. Tie a second knot exactly 57 cm from the ruler. Leave the rest of the string, we'll use that for the second technique for creating the 'Small Triangle'.  

A small triangle 57 cm high with a base of 1 cm subtends 1°. So what? The general equation for  using a 'small triangle' for measuring distance off is shown in the illustration above. By introducing degrees into the equation and simplifying it, we can create a formula that is easier and more flexible in use:

                                     60 times Width of the target (in miles)
Distance off (miles) = ------------------------------------------------------
                                    Target angle in degrees as viewed on the kamal

Mnemonic: Sixty miles [per hour] over degrees.

Example: Looking at the chart, I see that the distance between a water tower and a building on top of a hill is 2.3 miles. I grab the 57 cm knot of the kamal with my teeth, keeping the kamal extended and perpendicular to the string, I align the 0 mm mark on the water tower and note that the hill-top building is at 5 cm (which is 5 degrees).

                                                 60 times 2.3
So the Distance off in miles = ------------------
                                                         5

60 divided by 5 is 12. 12 times 2.3 is 2 times 12 (= 24), plus 0.3 times 12 (= 3.6) for a Distance off of 27.6 miles. 

This formula above works when the target Width is expressed in miles. Let's modify the formula so that it works with a target Width expressed in feet.

                                    Target Width in feet
Distance off (miles) = --------------------------------------------------------------------
                                    100 times target angle in degrees as viewed on the kamal

Mnemonic: My feet are over a hundred degrees.

Example: 
I'm heading for Mantaloking Bridge which has a vertical clearance of 30 feet.  Using my kamal, but holding it vertically, I align the 0 mm mark with the water and note that the bottom edge of the bridge itself is at 0.5° (5 mm).

                                     30                  30
Distance off (miles) = ---------------  = -----  I'm approximately 3/5ths of a mile from the bridge.
                                    100 times .5   50

How to Measure Distance Off with a 'Wink'


In the discussion above, the base of the 'small triangle' is the kamal (a 15 cm ruler) and height of the triangle is 57 mm. What if we use the distance between our eyes as the base of the triangle and 10 times that distance as the height of the triangle? 

If we do, we can hold up a pointer (finger, pencil, kamal...) at a distance of 10 times our eye 'span', sight on an object (e.g., a bridge from shore to shore) with one eye and then (without moving), sight with the other eye, the pointer will seem to 'jump' across the bridge. The length of the 'jump', measured on the object, is Width in the formula in the illustration below. 


If the 'jump' crosses the bridge in one jump, then the 'distance off' is 10 times the known width of the bridge. If it takes 4 'jumps' to cross the bridge, then 'distance off' is 10 times 1/4th of the known width of the bridge. If it the 'jump' spans 3 times the width of the bridge, then 'distance off' is 10 times 3 widths of the bridge.



The average ratio of eye span to arm length is 10:1. To make the 'winking technique more accurate, do the following:
  • Measure the distance between your pupils by looking into a mirror with a metric ruler aligned just below your pupils. My eye span is 61mm.

  • On the string attached to my kamal, I tied another knot at 61cm (10 times MY eye span) from the kamal.

  • When using the 'winking' technique, I just hold the 61cm knot in my teeth and stretch out the string and use the kamal on edge as the pointer. 

The beauty of the 'winking' technique for measuring distance off is that all you need is the 'width' of the object, be it the horizontal opening of a bridge... the distance between two jetties... size of a large building. The calculations are easy: Distance off = 10 times the estimated width of one 'jump' (on the object). The answer will be the same measure as the measure of the object width, i.e., feet to feet, meters to meters, miles to miles. 

Example: I'm rowing south of Mantaloking Bridge, where the horizontal opening is 24 m (from my notes I wrote on my chart during my preparation work). I align the pointer with the left side of the opening using my right eye. When I close my right eye and use my left eye (a wink), the pointer 'jumps' to twice the width of the horizontal clearance. So the width of the jump is 48 m on the object. Therefore the distance off is 480 m or 0.48 km. 


Summary


Below is a summary of the key formula and factors (room to personalize it for yourself) for the piloting materials we covered so far. I've personalized my copy, water 'proofed' it with clear spray and glued it to the back of the map holder I made for myself... see Part 2 for the map holder. (Click on the image below to enlarge it.)


The Fine Print


I’m not a professional pilot. I try to be accurate and I check my information, but I’m not perfect. This post is for information purposes and is intended to be only a starting point for learning the skills of piloting. As with any activity with a small boat, there is always the opportunity for ugly surprises. Practice the skills under ideal circumstances and you’ll increase the probability of being able to use the skills during an ugly surprise to keep you and your boat safe.

Sunday, November 27, 2016

Michalak's Batto

Batto is a Jim Michalak design.... plans available on Duckworks.

Jim Michalak's Batto

It is based on Pete Culler’s clipper bateau “Otter” which is lap strake rather than plywood stitch and tape as is Batto.

Specifications:


Length: 18' (5.5 m)
Beam: 36" (914 mm)
Water Line Length: 15' 11" (4.8 m)
Water Line Width: 23" (584 mm)
WLL/WLW Ratio: 8.3:1
Hull  Speed: 5.3 knots, 9.8 kph, 6.1 mph

Wojtek Baginski from Poland built a Batto for oar cruising in Poland and Germany.

Wojtek's Batto

The modifications that Wojtek made were to add fore and aft decks, modified gunnels (as he diagrammed below), added a skeg and a custom outrigger. The outrigger consists of two parts with an overlap joint in the center held together with bolt, and four bolts that hold the four ‘arms’ to the gunnel. Though not pictured, he has added Gaco oarlocks and is building a sliding seat rig.

Wojtek's Gunnel Modification on his Batto...

...the Finished Boat with Prototype Hoops for Tent Cover...

...and an Overhead Photo

Jake Millar built his Batto called “Needlefish”. It weighs 52.4 pounds (23.8 kg) and is beautifully finished. The shock cord ‘decking’ fore and aft is an interesting addition for holding oars, etc.

Jake Millar's Batto "Needlefish"

Needlefish Interior

Conversion to an Oar Cruiser:


To convert Batto to an overnight oar cruiser, I’d Add a water-tight bulkhead, with large access hatch, at each end of a 7’ (2.1 m) rowing/sleeping cockpit, eliminating the designed braces. I’d build a cross-planked set of floorboards for the cockpit, such as this...

Example of Cross-planked Floorboards

...to provide a dry sleeping platform and attachment points for rowing seat and foot rests… Add fore- and aft-decks, using skin-on-frame, resulting in a cockpit opening of 4’ to 5’ (1.2 m to 1.5 m) long. These decks would partially cover the ends of the sleeping area. Add a frame to support a ‘tent’, as Wojtek did, to provide sitting headroom and rain protection for sleeping. See the post on 'shelters' for other ideas for providing shelter. And finally, provide for a 4’ (1.2 m) oar lock spread… see outriggers for options to do this in addition to what Wojtek made.




Sunday, November 20, 2016

Piloting Part 3, Where Am I?

If I’m in familiar waters, I know where I am…  “Oh, there’s the red house, another 15 minutes and I’ll be at the ramp…”

But if I’m cruising in unfamiliar waters, then “Where am I?” is a more difficult question to answer because there is no ‘memory map’, no street signs, no mile/km markers, no “Welcome to Manahawkin” signs that tell me where I am.

Of course, a GPS system, with integrated charts, is the perfect solution. But if we don’t have one, then we need to determine “Where am I?” in other ways… the answer will be our ‘position’.

What do we Need to Find our Position?

  • Charts (essential)

  • …preferably in a case with a clear cover so we can mark our position without writing on the chart itself

  • A grease pencil (China Marker) that writes on the clear cover and can be erased (essential)

  • A boat compass (essential)

  • A protractor and ruler/straight edge (essential)

  • A hand bearing compass would be helpful, but not essential

  • Binoculars (or monocular) would be helpful, but not essential.

When we find our position, we record it on the chart cover. That recorded position (called a “fix”) is identical to what the GPS system does on it’s digital chart.
Given that we at least have the ‘essential’ tools to find our position, how do we do it?

Ranges 

A “range” is the alignment of any two objects that are represented on the chart and can be seen from where we are in our boat. (Note, in British usage, a ‘range’ is called a ‘transit’.)
Examples of ranges:
    • A Light house and the end of a peninsula 
    • The edge of two islands
    • A water tower and a draw bridge

When we, sitting in the boat, are aligned with two objects that are represented on the chart, we can draw a line on the chart through the two objects… we will be someplace on that line… it’s call a “Line of Position”, an LOP.
If there is another range (preferably at 90°, plus or minus 30°, of the first range), then draw the second LOP… where they cross is our position, a very accurate fix.

In the real world, we may not be able to find TWO ranges at the same time. There is another way to determine an LOP.

Compass Azimuth

 

 Note: "Azimuth" and "Bearing" are often used interchangeably, but technically that is incorrect. An ‘azimuth’ is an angle between 0 and 360 degrees measured from North. 

True azimuths (marked on your chart with a lower case “t”) are measured from ‘true’ north, the North Pole. Note that maps and charts are displayed with the top of the chart facing true north.
Magnetic azimuths (recorded with a lower case “m”) are measured from the Magnetic North Pole. The angle between the True North Pole and the Magnetic North Pole is called ‘declination’. See the planning post for definition and use of declination.  
“Bearings” consist of an angle in degrees (0 to 90) and 2 quadrant letters. For example “N 45° E” is Northeast, and “S 45° W” is Southwest. The first quadrant letter is always either "N" or "S" and the second is always either "E" or "W". I’ll use “azimuth” in these posts to be consistent and to match compass readings, which are 0 to 360.
A “compass azimuth” is the compass reading from the object to the boat. We can use a compass azimuth in order to establish an LOP (which, when plotted with another LOP, determines our position, a fix).  
 
How do we do we determine the azimuth from the object to the boat? Five steps: 
    1. If you are using a hand held compass, go to step 2.

      Otherwise, align the boat with the object:

      a. With a reverse reading compass, align the object over the center of the transom so that you are rowing AWAY from the object.

      b. If a kayak, canoe or sail boat (using a standard reading compass), align the object over the bow so that the boat is moving TOWARD the object.

    2. Note the compass reading (a magnetic azimuth) to the object.

    3. Apply the declination to the reading to get a true azimuth. (To convert a magnetic azimuth to a true azimuth, ADD the declination.)

    4. If you are using a reverse reading compass such as a Richie Rowing Compass, the result of step 3 is the true azimuth from the object to your boat and go to step 5.

      Otherwise (i.e., you are using a standard reading compass or a hand held compass) take the 180° reciprocal of step 3 result.

      For example, if step 3 result is 35°t, the reciprocal is 215°t… if step 3 result is 230°t, the reciprocal is 50°t.The result of steps 1, 2,  3 and 4 is the true azimuth from the object to your boat.

    5. Plot the true azimuth on the chart (cover) by placing your protractor centered on the object. Align a ruler from the center of the protractor through the azimuth (on protractor) and draw a line. This line is an LOP… the boat is someplace on that line.
Example: I use a Richie Reverse Reading compass on my boat. The declination in my area is 13° West (-13°) Let’s say I’m rowing north in Barnegat Bay (New Jersey) someplace west of Barnegat Lighthouse… I want to know exactly where I am so that I can set a compass course to my next anchorage at Tices Shoal.

Barnegat Bay West of Barnegat Lighthouse

Since I’m heading north, I turn the boat slightly to line up the center of the transom with the west end of Conklin Island…the compass reading is 54°m and I add -13 to it to get the true azimuth of 41°t.  Using a protractor centered on the west end of Conklin Island and using a ruler, draw a line at 41° (remember, its the azimuth from the object to the boat).
I turn the boat west to align the center of the transom with Barnegat Light, the compass reading is 286°m, add -13 to get true azimuth 273°t from the Light to my boat. Using the protractor centered on Barnegat light, draw a second LOP at 273°. Where the lines cross is my current position, a fix.

Position Plotted

Note that I did not have to take the 180° reciprocal (Step 4. above) because I’m using a reverse reading compass.
There is another way to estimate my position, answering “Where am I?”. It consists of a compass azimuth to a visible object on land, or a range (as described above) which tells me I am someplace on the resulting LOP, and an estimate of my distance from that object.
What are the various ways to measure distance to an object?

Geographic Distance

Because the earth is curved, a more distant object will appear lower than a closer object. The formula for determining “geographic distance” in miles is:

Square root of eye height (feet) above water plus square root of height (feet) of object above water
Distance (miles) = √Eye height (feet) + √Object height (feet)


Note: Due to atmospheric conditions such as haze, the practical limit of this technique is only about 15 miles...and that would be on a clear, calm day.  
 
Example: In my boat, my eye height is about three feet. The square root of three is about 1.7. This means my ‘water’ horizon is 1.7 miles away (√3 + √0 = 1.7). 
 
Example: I’m rowing north of Barnegat Light (172 feet above sea level). The break between the red top and white bottom is at about 85 feet. That color break point has just dipped below the horizon as I’m rowing. That means I’m about 10.9 miles north of the Light (√3 + √85 = 10.9). 
 
If I combine this ‘distance’ with a compass azimuth to the light, I’ve a reasonably accurate fix of my current position.

Barnegat Light

Example: I’m rowing in Round Valley Reservoir, returning to the ramp, and I see my friend in his kayak. I can just see his yellow life jacket, but not the kayak. I assume the bottom of the jacket is about a foot above the water (binoculars would help.)  This means he is about 2.7 miles away (√3 + √1 = 2.7).

Distance Off


In kayaks, sailboats and motor boats, there’s a technique called “Doubling the Bow Angle”. Let’s assume you know how fast you are going and that your course won’t change. You see a flag pole 30° off the port bow. You start timing. When the flag pole is 60° off the port bow (the angle has doubled… you can use any angle, e.g., the flag pole could be at 13° and second reading would therefore be at 26°), you stop timing and calculate how far you have traveled. The distance traveled is equal to the distance from your current position (when the flag pole is at 60° (or 26°)) to the flag pole.

If the initial sighting of the flag pole is at 45°, doubling the angle is 90° and now you know how far you are from the flag pole perpendicular to your course.

But if you are rowing, ‘doubling the bow angle’ isn’t very practical (unless you are using a FrontRower) because you are facing backwards and you’d have to turn around to get the bearings to the flag pole.

However, you can do this: while rowing a steady pace and course, you spot an especially tall tree on the shore 90° to your course (put the handle of the oar in the opposite oar lock and you’ll have 90° to your course.) Count the number of strokes it takes until the tree is 45° from your course. Multiply the number of strokes times your ‘standard’ distance covered per stroke. That distance times 1.4 is the distance you are then away from the tree (at 45°). (In a 45° right triangle, the hypotenuse is 1.4 times the length of a side.)

How do you determine 45°?

Consider the diagram below… if I spread my left hand, it forms the angles shown in the diagram. The little finger pointing over the center of the transom. I can measure 45° by sighting down my index finger. Palm down for bearings on one side and palm up for bearings on the other side.

Your Hand as a Protractor

Example: I’m rowing a steady 20 strokes a minute, at 16 feet per stroke, on a steady course of 40°m.

To my right, I see a small pier at 90° to my course. I start counting strokes and periodically check the bearing to the pier AND maintain a steady course of 40°m. When it’s 45° off my track, I stop counting at 113 strokes.

16 times 113 is 1600 feet (100 X 16) plus 208 feet (10 X 16, plus 3 X 16) for a total distance rowed of (call it) 1800 feet. 1800 times 1.4 (1800 plus 4 X 180) is 2520 feet from the pier. If I combine this with a compass azimuth to the pier, I have my current position.

This post has been about determining; “Where am I?” There are other techniques to help answer that question we’ll cover in Part 4 of this series on Piloting.

The Fine Print


I’m not a professional pilot. I try to be accurate and I check my information, but I’m not perfect. This post is for information purposes and is intended to be only a starting point for learning the skills of piloting. As with any activity with a boat, there is always the opportunity for ugly surprises. Practice the skills under ideal circumstances and you’ll increase the probability of being able to use the skills during an ugly surprise to keep you and your boat safe.

Sunday, November 13, 2016

The Pacific Troller Dory

Paul Butler, in his Butler Projects site, has the plans for a very nice row boat called the Pacific Troller Dory that could be easily converted into a row cruiser as we have described on this site.

The Pacific Troller Dory with the Designer at the Oars


...Under Construction

A Fish's View

Specifications:

  • Length:15' 4" (4.7 m)
  • Beam: 48" (1219 mm)
  • Estimated Water Line Length: 12' 4" (3.8 m)
  • Est. Water Line Width: 24" (610 mm)
  • Est. WLL/WLW Ratio: 6.2:1
  • Est. Hull Speed: 4.7 knots, 8.7 kph, 5.4 mph

Dan Moore (on building the Pacific Troller Dory)...

“…After gathering all the necessities, it took me about 6 weeks to build. Real time working on the boat was a lot less. The boat is a dream to row. With a GPS I can row to 6 mph, can hold 4.5 mph for hours…
I was a little apprehensive about taking another person in the boat. Thinking it might not trim as well and affect the rowing. It makes almost no difference with a combined weight of 370 lbs. It still does 6 mph on the top and rows nearly as easy. It tracks perfectly and holds well in a wind.“
A Sea Gull's View

Paul Butler (designer)...

“Construction is a straightforward process of stitching five full-length plywood panels together with plastic ties, then sealing seams with glass tape. No building base is required and bulkheads serve as forms to hold panels in alignment during assembly. To further streamline building, both ends of the gun dory are identical so the same plank pattern can be used 4 times. The hull interior is clean and open with none of the ribs, frames or stringers of traditional construction, making it easier to maintain, clean and repair. Hull reinforcement is provided by four full length chines, compartments, butt-blocks, seats and gunnel lamination. The hull exterior may be sheathed with glass cloth or glass tape can be laid over seams to save weight.”
Built in Norway, Used for Hunting and Fishing

She can be rowed, paddled, electric trolling motor either in a well or on an arm clamped on the gunnels at the stern… one builder even set it up to sail, with a centerboard, rudder and lateen rig.

Converting to an Oar Cruiser:

As I would do with all open boats, I would make the following additions to convert it to an oar cruiser:

  • Move the two bulkheads so they are approximately 7 feet (2.1 m) apart, accessible by large bulkhead mounted waterproof hatches,
  • Add decks fore and aft, using skin-on-frame to minimize weight,
  • Add transverse style slatted floorboards to provide anchor points for the rowing seat and foot rests (and a dry sleeping platform),
  • Provide a 'tent' cover for sleeping and eating out of the rain... see shelter options for various ways to accomplish this.

Plans include detailed building instructions with options for materials, interior layout, and customization…


Sunday, November 6, 2016

Car-topping Your Oar Cruiser

Car-topping is an alternative to trailering your boat… appropriate for light boats, although very long heavier boats can also be car-topped.

Articles


Jim Michalak on car-topping.

Jim Michalak diagram for dinghy loading

Seth Miller's article in Duckworks.

Seth's technique for adding an attachment point in the front of a car.

Roof Racks


An Australian Source for Roof Racks  (in case you don’t have any on your car).

Example of Roof Rack for a Subaru

...and a US source for roof racks.

Example from a US supplier

Loaders


Plans for a homemade side loader ... a complete set of photos and plans for a small boat loading system.

Example of plans for a slide loader

A commercial boat loader.

A commercial boat loader

Video of a homemade boat loader (ingenius!)

Screen capture of the 'tipping point' of the homemade boat loader

Let us know in Comments below of other techniques/equipment/tips for car-topping.