Thursday, December 24, 2020

What Length Oars?

 You built/bought a boat that needs oars. How do you determine what length of oars?

A rule-of-thumb is to double the span (the distance between the oar locks). However, this may not be the best length for the oars. For example, if the freeboard is greater than normal, then longer oars may be needed.

Having struggled with deciding what length of oars to make for my Ross Lillistone Flint, I created this worksheet.

Rowing Geometry Worksheet (Click on image to enlarge)

(You can download or print a full-sized JPG version of this worksheet from Dropbox.)

An Example:

For this Oar Cruiser, the span is 52" (1321 mm). The distance from the oar lock to boat's centerline is 26". The distance from waterline to bottom of the oar lock is 20 " (508 mm). I placed a dot at the intersection of these two dimensions on the worksheet above. 

Using an 8' 6" (scale) oar with a pencil mark at 7/25ths from the end of the handle. I placed that pencil mark on top of the dot and the blade just under the waterline, as in the photo below.

Rowing Geometry During the Power Stroke

This shows that when I'm rowing, the handles will almost touch (about 1" (25 mm) apart.

I then changed the oar to horizontal for the recovery stroke. Now the handles overlap about 1" (25 mm) which means on the recovery stroke, I'll have to cross my hands.

Rowing Geometry During the Recovery Stroke

Using this Rowing Geometry Worksheet, I've been able to confirm that 8' 6" oars will work.

See this post for additional information on rowing geometry. 

Friday, December 18, 2020

Another Oar Cruiser based on the Pacific Troller Dory

For this Oar Cruiser, I used an unmodified hull of Paul Butler's Pacific Troller Dory. I added decking and another alternative for weather protection while sleeping aboard.

Another PTD Based Oar Cruiser Buttoned up for Sleeping

Covering the cockpit are two hatches with fixed skylights. Two mooring/anchoring cleats and a fairlead at the bow facilitate anchoring without climbing on the foredeck. See writeup at the end of this post for details. 

While Rowing, the the Two Hatches are Stored on Deck

The hatches are held in place while rowing by side coaming extensions and a tie-down strap (not shown). The reverse reading compass is on the after hatch with a sight line from the rowing seat.

Top View Showing Slatted Floorboards, Rowing Seat (on left) and Foot Rest 

The outriggers hook onto the side coamings and are adjustable fore and aft and can be easily removed by sliding them forward and lifting them off the coaming. A detailed description of these outriggers is here.

Each side of the Hull is Fitted with Two 4" (102 mm) Clear Deck Plates

Two ports on each topside provide ventilation while sleeping. Oars are shown in racks would include tie-downs (not shown). The coaming is 4" (102 mm) high and includes oak strips enabling movable outriggers.

Specifications:

  • Length:15' 4" (4.7 m)
  • Beam: 48" (1219 mm)
  • Estimated Water Line Length: 13' 9" (4.2 m)

  • Est. Water Line Width: 24" (610 mm)
  • Est. WLL/WLW Ratio: 6.9:1
  • Est. Hull Speed:  5.2 knots, 9.6 kph, 6.0 mph

  • Cockpit length: 6' 6" (2.0 m)
  • Cockpit opening: 4' 6" by 24" (1.4 m by 610 mm)
  • Cockpit headroom with hatches: 24" (610 mm)

  • Two watertight end compartments: 2' 3" long (686 mm) by hull width
  • Two storage compartments (inboard of the two end compartments), with hinged openings, are 2' (610 mm) long by hull width
  • Span is 52" (1321 mm) suggesting 8' 6" (2.6 m) oars.  

Summary-Pros:

  • Plans are in the form of a booklet that describes every step for building the hull and is easy to follow.
  • The full decking and coaming add to the sea worthiness of an already sea worthy hull.
  • The two hatches, when closed, provide a weather proof sleeping cabin that will stand up to high winds from an evening thunder storm. 
  • She has sufficient protected storage for supporting a multi-day cruise.

Summary-Cons:

  • Too heavy to car-top.
  • Windage (top hatches stowed on decks) will be greater than a plain hull. Leave the top hatches at home when you use it as a day boat.
This PTD Oar Cruiser is, in my opinion, an effective compromise between a fast day boat, such as Gavin Atkins OarMouse, and other Oar Cruisers with temporary shelters.

Saturday, December 12, 2020

Andre-Francois Bourbeau's Gorfnik

Gorfnik  is an 8' (2.4 m) cruiser that is primarily sail propelled and uses a 'stand-up' paddle as auxiliary power. She has been extensively cruised in a wide variety of waters (see the write-up in plans description referenced in "Plans:" below.) Andre-Francois used the PDR hull design and then added a 'cabin' and decking to enable cruising with sleep-aboard accommodations and sufficient storage to be totally self-sustaining for at least a week.

Gorfnik with Spars, Paddle and Anchor Stored. Leeboard in Raised Position.

Classic PDR Hull with Rudder Raised in Michael Storer-Style Holster

Birdseye View Without the Two Hatches of the Cabin Top

Cabin with the Designed Access Port to Side Storage Compartments


Plans:

Free plans are available on the PDRacer site.

Specifications:

  • LOA: 8' 4" (2540 mm)
  • Beam: 4' 2" (1270 mm)
  • WLL: 7' 3" (2210 mm)

  • WLW: 4' (1219 mm)
  • Two side compartments full length of hull, full height of hull and 6" (152 mm) wide
  • Freeboard: 13" (330 mm) to deck

  • Sail: Sprit rigged, 66 Sq. Ft. (6.13 sq. m)
  • Mast: 12' 6" (3810 mm)
  • Sprit: 11' 6" (3505 mm)

  • Boom: 8' 0" (2438 mm)
  • Cabin top without hatches: 2' 5" by 2' 5" (737 mm by 737 mm)
  • Headroom from sleeping platform: 36" (914 mm)

  • Headroom from removable seat: 24" (610 mm)
  • Fore Deck: 4' 0" by 3' 4" (1219 mm by 1016 mm)
  • After Deck: 4' 0" by 1' 3" (1219 mm by 381 mm)

  • Side Decks: 8" (203 mm)
  • Rudder Blade: 3' 3" by 10" (991 mm by 254 mm)
  • Paddle: 7' 9" (2362 mm)

  • Leeboard (starboard side only) 3' 0" by 10 " (914 mm by 254 mm)
  • WLL/WLW ratio: 1.8:1
  • Hull speed: 3.6 knots, 6.7 kph, 4.0 mph

Possible Modifications:

  • Make the side compartments 8" (203 mm) wide and make them open topped rather than accessible by a port. This would eliminate the 'flotation' that the closed compartments provide, but would provide significantly more accessible storage.
  • Add oarlocks to the forward end of the sides of the cabin at the top (see example in Skow 244) in order to row standing up facing forward, eliminating the 'stand-up paddle'.
  • I would make sure that the removable seat would be low enough and risers long enough that I could sit in both the aft end and the forward end of the cabin without hitting my head on the top hatches. This may require building the hatches with a greater arch than plans show.
  • I would add skylights in the two top hatches so that I could see the sail when the hatches are closed.

Summary-Pros:

  • A mini-cruiser that I can sleep, cook and eat in, protected from rain, without having to set up a temporary shelter.
  • Capable of at least a week-long cruise.
  • Can be sailed and rowed (with the modification).
  • A full set of (free) plans that make it a straight-forward build.

Summary-Cons:

  • Short WLL will keep speed low.

Friday, November 27, 2020

Gavin Atkin's OarMouse as a Day Boat

 Gavin's OarMouse is a V-bottom 14 foot row boat made from two 4' by 8' sheets of plywood... one person, fast and easy to build.

Overview of OarMouse plans by Gavin Atkin


Plans are free and available at Duckworks.

Using the plans, I built a concept model (scale 12:1) of a day boat based on OarMouse. 



The view above shows the 6' 3" (1905 mm) cockpit, 10' (3 m) oars, reverse reading compass, slatted floor boards that enable the foot brace and rowing seat to be adjusted to fit the rower, and the outriggers which are also adjustable and which provide a span of 5' (1524 mm).


Profile View: Why Windage is Not an Issue



No technical reason why the reverse transom other than I like the way it looks. And "Roci..." is a "hero" of one of my favorite science fiction series: The Expanse (James S. A. Corey). 


The Bow Transom Sloped Forward 30 Degrees

Fitted Out with Sleeping Tent 

Specifications of the Day Boat:

  • LOA: 15' 6" (4.7 m)
  • Beam: 3' (914 mm)
  • Cockpit opening length 6' 3" (1905 mm)
  • Cockpit width 1' 9" (533)
  • Cockpit length (for sleeping) 7' (2.1 m)
  • Water Line Length: 15' (4.6 m)
  • Water Line Width: 30" (762 mm)
  • WLL/WLW Ratio: 6:1
  • Hull Speed: 5.2 knots, 9.6 kph, 6.0 mph

 Conversion of OarMouse to a Day Boat:

  • Lengthened the LOA from 14' to 15' 6" (4.7 m) by re-spacing the stations to achieve a 15.5' length. 
  • Slanted the aft transom forward by 30 degrees.
  • Slanted the bow transom forward by 30 degrees. Note that these 3 changes were the only changes to the hull shape/size in the original plans.

  • Made the two frames into two waterproof bulkheads 7' (2.1 m) apart providing generous flotation in the two end compartments.
  • Surrounded the cockpit opening by 3" (76 mm) high coaming.
  • Added a 4" (102 mm) V-shaped splash guard to the forward deck.
  • Added a fairlead to the bow. See this article (at the end of the post) for how to anchor from the cockpit without crawling out on the fore deck.
  • Provided outriggers. See this post for a description of these outriggers.
  • Provided demountable hoops for supporting a shelter.

Summary-Pros: 

  • A straight forward build from the free plans.
  • She will be one of the fastest boats of all those in this blog.
  • The full-decking, coaming and splash guard will result in a more sea-worthy boat than an open version of the hull. However, she is only designed for protected waters.
  • Very low profile means she will be little affected by cross-winds when rowing.
  • Plenty of storage space in the cockpit for supplies in waterproof bags. 
  • Two waterproof compartments provide flotation.
  • Long boats such as this can be car-topped.  See the comment by John Welsford at the end of this post.

Summary-Cons:

  • The narrow V-bottom hull makes this boat tippy (but fast). Keep weight low and centered. See John Welsford's technique for reboarding long narrow boats such as this.
  • No built-in waterproof storage.

This boat would be ideal for day trips in protected waters. A boat that moves through the water this easily is a joy to row. 








Friday, November 13, 2020

Jim Michalak's Batto as an Oar Cruiser

 Batto was introduced in this post. Following is one possibility for converting her into an Oar Cruiser.

Batto the Oar Cruiser ("Camo") Camouflaged for Stealth Anchoring,

Camo's 'Shelter Hoops', Outriggers, Deck Hatches and Floor Boards
See this post for more information about the Outriggers. And this one  for shelters.

Bird's Eye View

 Reverse Sheer & 4" (102 mm) Coamings
Reason for the forward sloping transom (about 30 degrees from vertical) is purely a personal one... I like the way it looks. 

Bow-on, Showing Splash Guard and Dory-like Cross Section

Conversion to an Oar Cruiser:

  • Reduced the height of the stem by 11" (279 mm) resulting in 10" (254 mm) freeboard at the bow.
  • Made the width of the topsides at midships 18" (457 mm) resulting in 15" (381 mm) freeboard to the bottom of the cockpit coaming.
  • Lowered top of the transom 5" (127 mm) resulting in 10" (254 mm) freeboard at the top of the transom.
  • Drew a new sheer line (using a long batten) through these three points to produce the reverse sheer (lowering windage) on the topside panels.
  • Both topside panels will fit within 48" (1219 mm) wide plywood but the bottom panel will have to come from one additional plywood sheet.
  • Replaced the temporary frame at station #6 with a permanent bulkhead (crowned 2", 51 mm).
  • Replace the temporary frame at station #12 with a permanent bulkhead at station #13 (crowned 2", 51 mm).
  • Between these two bulkheads is the cockpit 7' (2134 mm) long.
  • Added a foredeck 6' 3" (1905 mm) from stem to 14" (356 mm) aft of the bulkhead at station #6.
  • Added an afterdeck 5' 11" (1803 mm) from top of the transom to 14" forward of station #13.
  • Added side decks 9" (229 mm) wide at midships.
  • Resulting cockpit opening is 4' 8" (1422 mm) by 2' 3" (686 mm).
  • Cockpit opening is rimed by a 4" (102 mm) high coaming.
  • Two hatches, 1' 10" by 1' 7" (559 mm by 483 mm) installed on the two decks to enable access to the fore and aft compartments.
  • Added cross-slatted floorboards to provide adjustable attachment points for the rowing seat and foot braces.
  • Added outriggers that provide a span of 48" (1219 mm), appropriate for 8' (2438 mm) oars.
  • Add provision for a shelter (see shelters) for alternatives.

Specifications of "Camo":

  • LOA: 17' 9" (5.4 m)
  • Beam: 45" (1143 mm)
  • Weight Est: 110 lbs (50 kg)
  • WLL: 16' (4.9 m)
  • WLW: 26" (660 mm)
  • WLL/WLW Ratio: 7.4:1
  • Hull Speed: 5.4 knots, 10 kph, 6.2 mph

Summary-Pros:

  • High WLL:WLW ratio (7.4:1) make Batto one of the fastest Oar Cruisers. A builder's comments (Ray Schaefer): "Slick as snot. Fastest fixed seat I ever rowed. It's a pleasure to row into a good wind and make good progress."
  • A cruising speed of 4.5 mph (7.2 kph) for ten 45" sessions per day results in 34 miles (54 km) a day cruising.
  • Lowering the bow and stern, and increasing freeboard midships (a reverse sheer) reduces windage, adds freeboard in cockpit area and keeps the underwater lines as designed by Jim.
  • Adding decks, coaming and splash guard to her dory-like cross section make her even more seaworthy.
  • The two water-proof compartments provide storage as well as emergency flotation

Summary-Cons:

  • The addition of decking and bulkheads adds approximately 20 pounds (9 kg) to her weight. Long narrow boats such as this can be car-topped by one person.
  • Narrow hulls (at the bottom) like this are fast but the compromise is increased tenderness and limited room in cockpit.

 

A Casco Bay Overnighter:

She had launched near Falmouth (Massachusetts) and was heading for Popham Beach, about 23 miles (37 km) ENE. Wind was Force 1 out of the west. She went through the islands and was about 1/4 of the way to Popham when the wind backed around to the SE, and increased in strength. Within an hour, she was struggling to maintain an ENE course with Force 4-5 winds abeam. She had relaxed her strangle hold on the oars, which helped to relax her arms and back. She had changed 'gear' on the oars to give more power in her stroke. She timed the 'hard pulls' when she was in a trough. Progress was still slow. She tried changing course to east, but then her boat corkscrewed as each wave passed. She missed a couple of strokes, throwing her timing off.

She was tired. She decided to head NW, running before the wind, heading for the south end of Jewell Island where she could loop around behind the island and find a little cove to tuck into and anchor. The seas were building and she needed to be careful not to broach. She was able to control the forward way on her Oar Cruiser using just the oars by back stroking when the wave lifted the stern. She was aiming for the 800' (250 m) gap between Inner Green Island and Jewell.

As soon as she was through the gap, she headed NE and ducked in behind Jewell. On her chart, she saw the perfect spot a little less than a mile away. She rowed comfortably in the lee of Jewell, anchored in Cocktail Cove that gave her protection for a good night's sleep.

She thought, "I'll get an early start in the morning, before the wind picks up, and continue on to Popham Beach." And that's what she did.


Wednesday, October 28, 2020

Phil Bolger's Cartopper as an Oar Cruiser

Note: In an earlier post, I stated this concept model to be Jim Michalak's Oarcle design. Oarcle and this extended Cartopper are very similar. I was confused.

 In a Jan. 8, 2017 post we introduced Bolger's Cartopper. On Apr. 30, 2017 we presented a 'sail/oar' version which converted the 12' (3.7 m) Cartopper to a cruiser. Described here is the Cartopper extended to 15' 6" (3.81 m) to create an Oar Cruiser.

A Proposed Oar Cruiser (Rowmance) Based on Cartopper

Bow, Showing the 'Fairlead' Used for Anchoring. See How This 'Fairlead' is 
Used for Anchoring at End of This Post.

Cockpit with Rowing Seat and Foot Rests Clipped to Floor Boards

Shelter Provided by PDR Tube Tent (See Shelters)

Specifications:

  • Length: 15' 6" (4.7 m)
  • Beam: 43" (1143 mm)
  • Water Line Length: 13' 10" (4.2 m)
  • Water Line Width: 37" (940 mm)
  • WLL/WLW Ratio: 4.5:1
  • Weight: (Est.) 100 lbs (45 kg.) with added decking
  • Hull  Speed: 5.0 knots, 9.3 kph, 5.8 mph
  • Cockpit length; 7' (2134 mm) 
  • Span is 4' 3" (1295 mm) needing 8' (2438 mm) or 8' 6" (2591 mm) oars 

Changes to Make the Oar Cruiser:

  • Added decking forward and aft, ending at the two bulkheads, with hatches let into the decks to provide access to the compartments
  • Added side decks to help support 4" (102 mm) coaming surrounding the 4 sides of the cockpit opening which also supports the outriggers. See here for how these outriggers are used.
  • Added cross-slatted floorboards. See Floorboards to see how foot rests are 'clipped' to cross-slatted floorboards.

Summary-Pros:

  • For plans I used Bolger's book, Boats with an Open Mind, (Chap. 7).
  • Reduced the height of the stem and transom slightly and raised the freeboard midships, all to reduce windage (but not changing the underwater lines in any way.)
  • The resulting boat will be sea-worthy, comfortable and provide sufficient dry storage needed for week-long singled-handed cruises.

Summary-Cons:

  • She will not be the fastest Oar Cruiser, but will certainly be able to maintain 3 knots. (Three knots for 45" an hour for 10 hours a day is 25 miles.)
  • 100 pounds (45 kg) and moderate LOA would make car-topping difficult for one person. 
This extended version of Cartopper worked out very well and would be an excellent Oar Cruiser.

Monday, October 26, 2020

Mark Wallace's Black Skiff Strip Built

 In an earlier post we introduced Mark Wallace's Black Skiff. In this post we'll present a variation in which construction is done with strip planking. The result is a model of Mark's design using his free plans.

Overview

Profile

Fish Eye View

Modifications of the Design:

  • Strip planked rather than the plywood panels in the original design.
    • In the model, I used 1/32 (0.34 mm) by 1/8 (3.175 mm) strips.
    • If I were to make a full sized boat, strip built, I'd use 1/4 " (6 mm) strips ripped from 3/4 "(19 mm) Western Red Cedar planks and router one edge concave and the other edge convex using router bits set such as these.
    • I set up three forms (adapted from the frames on the plans) mounted upside down on a ladder frame. (Note that the next time (model or full size) I'd use five forms.)
    • I laminated and installed the two stems attached to the bottom.
    • I then installed the flat bottom. The sizes and shapes of both stems and the bottom came directly from the plans. 
    • I then laid in and glued the strips starting at the bottom and working 'down' to the gunnels. (Note; Installed each strip on alternate sides of the boat).
    • Because the center frame was eliminated, reinforced the topsides by installing an inwale separated from the hull by spacer blocks.
    • Installed two full sized bulkheads 7' 4" (2235 mm) apart centered midship. Each bulkhead has a15" by 18" (381 mm by 457 mm) hatch to provide access to the respective compartment.
    • Installed two decks crowned 2" (51 mm) running from each bulkhead to the stem and stern.
    • Provided a rowing seat that rests on slats attached to the hull.
    • The span of 4' (1219 mm) called for oars 8' (2438 mm) long.
    • Added floorboards.

    Specifications:

    • LOA: 14' 3" (4.3 m)
    • Beam: 4' 2" (1270 mm)
    • Water Line Length: 11' (3.4 m)
    • Water Line Width: 33" (838 mm)
    • WLL/WLW Ratio: 4:1
    • Hull  Speed: 4.4 knots, 8.14 kph, 5.1 mph

    Summary-Pros:

    • Will keep you safe in very rough conditions.
    • Plenty of waterproof storage for supplies (and emergency flotation.)
    • Easy to row.

    Summary-Cons:

    • Limited speed due to short WLL.
    • High windage would make rowing in a crosswind difficult.
    • Need to provide shelter for overnight sleeping using one of these alternatives.

    Black Skiff would make a very comfortable and pretty Oar Cruiser that would be welcome in any waters.

    Saturday, October 24, 2020

    Paul Butler's Pacific Troller Dory

     Paul's Pacific Troller Dory (PTD) is one of my favorite designs for an Oar Cruiser. See Nov.13, 2016 and Apr. 2, 2017 for variations on the design. Following is my most recent version.


    PTD as an Oar Cruiser



    Duck's Eye View


    Bird's Eye View


    Modification to the Original Design to Create an Oar Cruiser:

    • Lengthened the hull by 2' (610 mm). The hull is double-ended. So the plans only include half the boat. By extending the chine line by 1' (305 mm) from the center line of the plan, the boat will be 2' longer. 
    • Reduced the size of the (two) stems to 3" (76 mm) and added 2" (51 mm) to the height of the sheer line midships. Drew a smooth curve through these 3 points, creating a reverse sheer as pictured below.

    Profile of PTD Showing Reverse Sheer

    • Added two full-sized bulkheads at the same location as in the plans, 3' 10" (1168 mm) from the stems. These bulkheads have large hatches to provide access to the two storage compartments. The resulting cockpit is 7' (2134 mm) long.
    • Added decks (crowned 2" (51 mm)) fore and aft  and side decks 9" (229 mm) wide at midships resulting a cockpit opening of 5' (1524 mm) long and 1' 11" (584 mm) wide.
    • Added a 3" (76 mm) coaming on all 4 sides of the cockpit.
    • Even with the top of the side coamings, attached two 1" by 1" (25 mm) by 4' (1219 mm) oak ribs (one on the inboard side of the coaming and one on the outboard side) for holding the oar outriggers. 
    • Each of the two oar outriggers are triangular in shape with a 'base' of 12" (305 mm) and a 'height' (base to oar lock) of 1' 8" (508 mm). This generates a span of 4' 10" (1473 mm) on PTD. Either 9' (2743 mm) or 10' (3048 mm) oars would be suitable for this span. 
    • Attached to the full width of the bottom of the 'base' are two "L" shaped pieces (photo below) that enable the outrigger to slide fore and aft on the oak ribs on the coaming (a tight fit so they don't slide with pressure at the oar lock end of the outrigger) and yet stay horizontal and stay in their fore and aft position on the top of the coaming.

        Side View of One Outrigger        

    • Added full-length cross-slatted floorboards to provide a dry sleeping platform as well as anchor points for the foot rest and rowing seat.


    • On the foredeck is a 5" (127 mm) high splash guard for any water washing over the foredeck.

    Splash Guard and Anchor Cleat

    Specifications:

    • Length: 17' 4" (5.3 m)
    • Beam: 48" (1219 mm)
    • Water Line Length: 14' 4" (4.37 m)
    • Water Line Width: 33" (838 mm)
    • WLL/WLW Ratio: 5.2:1
    • Hull  Speed: 5.1 knots, 9.45 kph, 5.9 mph

    Summary-Pros:

    • Large enough to hold sufficient supplies and equipment for extended oar cruising.
    • With the added midship's freeboard, reduced windage at the ends, large decks and a dory's deserved capability for handling rough water, she can handle any rough water you may encounter in most inland waters.
    • The narrow bottom (20", 508 mm) and high WLL:WLW ratio (6.2:1) make this an Oar Cruiser that will get you to your next waypoint in good time.

     Summary-Cons:

    • Heavy enough to be awkward to car-top.
    • Initially tender, as are all narrow-bottom hulls.
    • Protection from rain (and bugs) must be provided using one of the many 'shelter' techniques in this site. 

     Mid-fall Cruise in Barnegat Bay:

    I could envision a mid-fall cruise down Barnegat Bay in this Oar Cruiser after most of the boats have gone to rest for the winter; anchoring off the many state/national parks and wildlife refuges south of Barnegat Inlet. Trailer parking and launch site at the east end of the Manahawkin Bridge would be good starting/end point. Weather would be cool, no bugs.  Thousands of migratory birds provide lots of companionship.

    Thursday, October 22, 2020

    Jerome Delaunay's Scow 244

     Not exactly an Oar Cruiser. It's a Sail/Oar Cruiser... emphasis on SAIL. It's 8' (2.44 m) long with a hull design very similar to the PDR, of which there are many variations. There is room to sleep aboard and carry supplies/equipment for a multi-day single-handed cruise. 

    Modifications:

    • Added oar locks to the forward end of the cockpit and included 8' (2.44 m) oars which need to be that long in order to work with the height of the locks above the water. The rower would stand, facing forward and push the oars to row. See Rowing Geometry for how to calculate that 8' (2.44 m) oars will work with a span of 3' 6" (1067 mm) and locks 2' 3" (686 mm) above the waterline.

    • Added a large hatch over the compartment forward of the mast. This compartment could be used for storage of the anchor and other wet/muddy items.

    • Rather than a solid bulkhead aft (supporting the forward edge of the rear deck), I opened up the bulkhead to provide more sleeping space resulting in a sleeping platform 6' 10" (2083 mm) long. 

    • If I were to build it full size, I'd increase the width of the side compartments from 6" (152 mm) to 9" (229 mm) to provide more storage capacity and only narrow the sleeping area by 6" (152 mm) (to 30" (762 mm)).

    • I'd make a drop-in framed bug screen that would fill the top of the rear bulkhead and to which the rear edge of the 'canvas' cover would be attached.

    • I'd add a simple removable thwart that spanned the storage compartments that could be used while sailing.


    Compartments on both sides, from bulkhead to bulkhead, provide storage. 
    The cockpit opening is covered with 'canvas' to provide a rain-proof night time.
    The horizontal handle on the pivoting leeboard should be pointing aft, not forward.



    The cockpit opening is 45" (1143 mm) long by
    36" (914 mm) wide while the sleeping platform
    is 6' 10" (2083 mm) long and 36" (914 mm) wide.


    The 'junk sail' is 65 sq. ft. (6.04 sq. m)
    Oars to be stored on side decks when sailing.

    Specifications:


    LOA: 8' (2.4 m)
    Beam: 4' 1/2" (1232 mm)
    Weight: 150 lbs (68 kg)
    Displacement loaded: 630 lbs (286 kg)
    WLL: 7' 3" (2210 mm)
    WLW: 4' 0" (1232 mm)
    WLL/WLW ratio: 1.8:1
    Hull speed: 3.6 knots, 6.7 kph, 4.0 mph

    Plans:


    The free plans for the Scow 244 are available from Duckworks.


    Summary-Pros:

    • Very complete plans leading to a straight-forward build
    • It has 26" (660 mm) headroom under the 'cuddy'
    • Storage space for supplies
    • Comfortable sleeping area 
    • Oar propulsion for maneuvering in tight spaces 
    • The PDR style hull has proven to be reasonably sea-worthy; A number of PDRs have sailed the Texas 200

    Summary-Cons:

    • Short WLL will result in a slow boat
    • As with any boat this small, headroom is an issue


    Tuesday, October 20, 2020

    Glossary

     Terms used throughout the blog:

    ·        3-, 4-, 5-, 6-, 7-Panel: The number of plywood panels making up the hull. A 3-panel hull (John Wellsford's Mollyhawk) has 2 side panels and 1 bottom panel. Michalak's LFH17 has 7-panels.

    ·        Aft: towards the back of the boat.

    ·        Andersen Mini Bailer: Available at Duckworks, [https://www.duckworks.com/product-p/ra554130.htm]

    ·        Back: As the wind direction changes, the direction can shift counter-clockwise (back) or the new direction can shift clockwise (veer) from the old direction.

    ·        Broach: As a boat is overtaken by waves, the stern of the boat rises and the boat starts to slide down the front of the wave. If the bow of the boat 'digs' into the back of the wave in front, the boat can suddenly turn (left or right) and end up sideways, a 'broach', and possibly flip over.

    ·        Bow: (Rhymes with "allow"). The front-end of a boat.

    ·        Bulkheads: Vertical panels (typically water-proof) within the hull that divide the boat into multiple sections.

    ·        Carvel planked: Similar to lapstrake, but rather than have the planks 'lap' over the next plank below, the plank edges are glued/epoxied edge to edge as in strip planking.

    ·        Car-top: Carrying the boat on top of the car's roof rack.

    ·        Chine: Looking at the hull from one end, the chine is the 'corner' where the bottom of the hull intersects with the sides of the hull.

    ·        Chine panel: The panel in the hull that replaces the 'corner' of the chine. It is the panel on each side of the bottom panel in a 5-panel hull.

    ·        Coaming: Typically 3- to 5-inch (76- to 127-mm) high barriers to prevent water from washing off the decks into the cockpit.

    ·        Cockpit: The space in a boat that is typically used to operate the boat.

    ·        Crown: the curve of a deck from one gunnel to the other gunnel.

    ·        Dagger-board: Used in a sailboat to reduce the tendency of a sailboat to go sideways when the wind is coming from the side. The Dagger-board trunk is the apparatus that holds the board vertical yet allows the board to be moved up and down without letting water into the hull.

    ·        Displacement: The weight of the boat, plus everything in the boat (people, supplies, equipment).

    ·        Double-ended: A boat that is pointed at both ends, such as a canoe.

    ·        Drop-in Rowing Unit: A rowing unit consisting of outriggers to provide span for the oar locks, foot braces, and a rowing seat that slides on rails. An example is the Piantedosi unit sold by CLC Boats and other vendors.

    ·        Flare: In boats, 'flare' refers to the angle of the sides of the hull from the vertical. A boat with no flare has sides that are vertical while a boat that has sides that are angled out 30 degrees (such as a "dory") has a lot of flare.

    ·        Floor boards: Typically made from wood and rest on the bottom of the hull in order to provide a small space between the bottom and where a person would stand, sit and/or lie down.

    ·        Floatation: That which keeps a boat from sinking when it is filled with water.

    ·        Foot braces (also known as foot stretchers): What the rower pushes against (with her/his feet) when rowing.

    ·        Fore: means front, toward the bow of the boat.

    ·        Frame: Various uses. In general, it is a set of 'sticks' that support either the deck or the sides and bottom of the hull. The frame can become an integral part of the boat, or can be a support system for building the hull of the boat, but does not become part of the boat after the hull is constructed. The latter are also referred to as Forms.

    ·        Freeboard: The vertical distance from the water to the gunnel at a given point.

    ·        Gunnel: The strips of wood that define the 'sheer-line' at the top of the hull sides (also known as gunwales).

    ·        Hatches: the 'doors' that close off openings that are either in the decks or in the bulkheads. They allow access to enclosed spaces in the boat and are typically water-proof when closed.

    ·        Hull speed: An approximation of the maximum speed (in knots) that an Oar Cruiser (any 'displacement hull') can travel. The formula; speed in knots equals 1.34 times the square root of the water line length (WLL) in feet. It is the speed at which the length (crest to crest) of the bow wave equals the WLL of the boat. Going faster than hull speed means that the boat is attempting to climb up the back of the bow wave. This article [http://antrimdesign.com/heavy-boats-light-boats-and-hull-speed.html] has an excellent explanation.

    ·        Inwale: The inner-most component of the 1, 2, or 3 pieces of wood that make up the gunnel. If used with a second inwale, the two inwales can be thinner (lighter) than just one, and they are typically separated by spacer blocks to create a girder-like support for the edge of the hull.

    ·        Knot: The nautical measure of speed; 1 knot equals 1.85 kilometers per hour and 1.15 miles per hour.

    ·        Lapstrake: Construction of a boat hull in which each strake (plank) over laps the top of the strake below.

    ·        Length of a boat (LOA): is the overall dimension from the bow to the stern.

    ·        Lines: 1. The drawn lines on the plans for the boat; as in "…keeps the underwater lines as designed." 2.  "Lines" also refers to ropes used on a boat; as in "…tie the bow line to the cleat on the dock."

    ·        Load waterline: The "line" on the hull made by the surface of the water when the boat is 'loaded' (with people, supplies and equipment).

    ·        Midships: In the middle of the boat.

    ·        Oar Cruising: Using small, oar-powered boats to cruise in where 

    Small means you can either car-top or trailer it by yourself, 

    Oar-powered means the primary propulsion is rowing and 

    Cruise means you can sleep in it and carry all the food and equipment you'll need for at least a week without re-supplying.

    ·        Oar locks: The "U"-shaped metal fittings that provide the pivot point for the oars.

    ·        Outriggers: In the context of row boats, outriggers are supports for the oar locks that extend beyond the sides of the hull.

    ·        Reverse Reading Compass: Available at Duckworks, [https://www.duckworks.com/product-p/rs-rrc.htm]

    ·        Rowing seat: The support for the person rowing.

    ·        Seaworthy: Refers to the ability of the boat (assuming a competent crew) to survive in less than ideal weather conditions.

    ·        Sheer: The top edge of the hull. Sometimes referred to as the sheer-line. The sheer-line can be straight, curved with lowest point of the line about 2/3 back from the bow of the boat, or it can be a 'reverse sheer' in which the ends of the sheer-line are lower than the middle portion.

    ·        Skeg: A fin attached to the bottom of the boat's centerline, typically starting at the transom. Provides directional stability as the boat moves forward.

    ·        Skin friction: As the hull moves, water applies frictional force to the hull surface (skin) which slows the hull, taking energy to overcome.

    ·        Sneak Box: One-person boats originally designed for hunting ducks (also known as Duck Boats) in which the deck is fastened to the bottom of the hull at the gunnel. The shape of the hull looks like the cross-section of a closed Clam.

    ·        SOF (Skin-On-Frame): A hull that consists of a light frame over which a layer of polyester or nylon water-proof cloth is attached.

    ·        Span: The distance between oar locks, typically 50% of the oar length for fixed seat rowing.

    ·        Splash guard: A "V" shaped barrier attached to the deck to prevent water washing over the deck from entering the cockpit. Typically used in low freeboard hulls and with coamings.

    ·        Stem: The (near) vertical piece of wood that joins the forward edges of the two (or more) side panels of the hull.

    ·        Stern: the back-end of a boat.

    ·        Strip plank: A method of building the hull of a boat by attaching to frames narrow (1- to 2-inches (25- to 51 mm)) strips of wood, glued edge to edge.

    ·        Tender: For boats, it is how 'tippy' a boat is. A kayak is very tender. A garbage scow is NOT tender, it's very stable.

    ·        Thwart: A narrow (10- to 12-inches (254- to 305 mm)) seat used for sitting that goes from one side of the hull to the other side. It typically also serves to strengthen the hull by bracing the two sides of the hull.

    ·        Topsides: The sides of a hull (verses the bottom and deck).

    ·        Transom: A (near) vertical panel at the end of the hull to which the sides, chine and bottom panels are attached, closing off the end(s) of the hull.

    ·        Trimmed: (As in, "Cartoppers row well as long as they're trimmed with one person…"). All the weights in the boat (people, equipment and supplies) are distributed so that the boat remains 'level' side to side and end to end; i.e., that it is floating parallel to its designed "load waterline".

    ·        V-bottom: A hull in which the end view of the hull's bottom forms a "V" (as opposed to a 'flat bottom' or 'round bottom' hull.

    ·        Veer: As the wind direction changes, the direction can shift counter-clockwise (back) or the new direction can shift clockwise (veer) from the old direction.

    ·        Wales: The strips of wood on the inside of the hull at the sheer line. Often there are two wales, the inner wale and the outer wale. These two wales are also referred to as the inwales. The two wales are often separated by a set of blocks so that the wales act as a girder to strengthen the edge of the hull. A second (or third) strip of wood on the outside of the hull at the sheer line is called the rub rail. The terminology for these strips of wood vary by designer/region/country.

    ·        Water Line Length, WLL, is length of boat at the waterline.

    ·        Water Line Width, WLW, is width of the boat at the waterline at the widest point.

    ·        Waypoint: A point on a chart or GPS screen that identifies the next location to be reached. Waypoints mark points on the chart/GPS screen which reflect the proposed passage of the boat.

    ·        Width of the boat: is the dimension at the widest point on the hull that measures from gunnel to gunnel.

    ·        Windage: Exposure to the wind which results in 'wind resistance'. 

    ·        WLL is length of boat at the waterline.

    ·        WLL:WLW is the ratio of these two dimensions. In general, the higher this ratio, the faster the boat can move.

    ·        WLW is width of the boat at the waterline at the widest point.