Pic

Pic
A Gear Shift for Oars, Courtesy of Chris Cunningham, Small Boats Monthly

Sunday, November 12, 2017

Change Gear when Rowing

(Note: This is a series of posts originally published 2016 each focused on a different aspect of powering small boats with oars. So far, we have re-posted the following topics:
  • Designs for various oars, including how to determine oar length... Sept 24
  • How to make a set of spoon-blade oars... Oct 1
  • The various ways to connect the oars to the boat... Oct 8
  • Alternative outriggers... moving the oar locks to a proper 'span' on a narrow hull...Oct 15
  • Various foot braces... Oct 22
  • Rowing geometry... Oct 29
  • Sliding seat/rigger options... Nov 5
  • This week, Changing 'gear' when rowing
  • Next week, Rowing in Wind

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Note: First published Jan 20, 2016

Change Gears When Rowing?

Yes, you can.

Why would I want to change gears? If you were riding a bicycle, you would want to shift to a 'lower' gear when going uphill, and a 'higher' gear going downhill.

When rowing, going against the wind (or current) and/or rowing a heavy displacement boat (thanks to Brian M. for suggestion to add 'displacement' factor) is 'uphill' (use a lower gear) and rowing with the wind or current with a light boat is 'downhill' (use a higher gear).

Let's define "gear" as it's used in rowing: Gear is the ratio of the outboard length of the oar to the inboard length of the oar.

The outboard length is measured from the tip of the blade to the pivot point on the oar at the oar lock and the inboard length is from the pivot point to the end of the handle.

My current set of oars are 8' (244cm) with an outboard length of 67.5" (171cm) and inboard length of 28.5" (72cm), resulting in a gear ratio of approximately 2.4 (171/72 = 2.375).

Koti, in the site referenced below, suggests the 'optimum' gear ratio is 2.5 to 2.7. If I moved the location of the pivot point closer to the handle by 1.75" (4.5cm), the gear ratio would be 2.6, right in the middle of Koti's optimum gear ratio.

So how do we change gears? Six ways:

1. Have two (or more) sets of oars with different gear ratios for different conditions. Long distance 'ocean' rowers carry multiple sets of oars, not only for safety, but also to deal with different conditions.

2. Move the locks. I've never seen this, but it certainly is feasible to have the oar locks mounted on blocks which could slide in or out and lock into position.

3. Move the collars -- the issue is that collars typically are permanently attached to the oar and can't be moved, although in competition rowing, the collar, also called the 'button', is moved to change gear ratio.

4. Slide the oar in or out on the lock. This works for a few minutes, but soon the oar slides out (butting up against the collar and thus to a higher gear).

5. Make oars with longer handles and move your hands out (toward the oar blade) for higher gear and in for lower gear. My oars have handles 5.5" (14cm) long. I can definitely feel the difference  in 'gear' with the approximately 1.5 (3.8cm) inches of hand movement available on these handles.

6. Add a small jam cleat (Duckworks Jam Cleat 'SD-002040') and 3 feet of 1/8 non-stretch line as shown the photo below. Tie a tight loop around the oar loom just outboard of the cleat, wrap the standing part of the line around the oar lock and back to the jam cleat. This provides infinite and quick adjustment.


Two other advantages of this 'gear shifter':

1. You can let go of the oars and they will stay in the oar locks while you take a photo or drink some water.

2. You really don't need collars (unless you are a "belt and suspenders" person).

Measure your own current gear ratio and add the 'jam cleat' adjuster to increase your rowing efficiency.

Comment below with your experience in using 'gears' when you row. I'd love to hear from you.

For a detailed discussion on oar length and gear ratios, see "Optimum Sculling Oar Length" http://koti.kapsi.fi/hvartial/oarlength/oarlen.htm#top

For more on the "Physics of Rowing", see http://www.atm.ox.ac.uk/rowing/physics/index.html

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Note: First published May 13, 2016


CATCH: Another Way to Change Gears


In the January post "Change Gears When Rowing?", six alternatives for how to adjust 'gear' (ratio of outboard to inboard length of oar) were presented. Chris Cunningham, in the April issue of Small Boats Monthly presented yet another way to control 'gear' when rowing.

"Thumb Buttons" to Control Gear on Oars
He put three of these buttons on each oar. The buttons are on the bottom of the leather when the oar is in the 'power' portion of the stroke. Included in the article is a video that shows how he changes gears while rowing without missing a 'stroke'.


(Text and photo used with permission from Chris Cunningham.)

Sunday, November 5, 2017

Sliding Seat/Riggers

(Note: This is a series of posts originally published 2016 each focused on a different aspect of powering small boats with oars. So far, we have re-posted the following topics:
  • Designs for various oars, including how to determine oar length... Sept 24
  • How to make a set of spoon-blade oars... Oct 1
  • The various ways to connect the oars to the boat... Oct 8
  • Alternative outriggers... moving the oar locks to a proper 'span' on a narrow hull...Oct 15
  • Various foot braces... Oct 22
  • Rowing geometry... Oct 29
  • This week, sliding seat/rigger options
  • And next week, changing 'gear' when rowing

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(Previously posted May 20, 2016)

Introduction


Sliding seat/riggers enable you to use your leg muscles to row, as well as your back and arms, increasing the power of your stroke. This post is about various alternative systems that can be used.

Sliding SEAT systems enable the rower to move while the oarlocks are stationary.

Sliding RIGGER systems enable the rower to be stationary (in his/her location in the hull) while the oarlocks move. The advantage of the sliding rigger systems is that the weight of the rower is not shifting fore and aft with each stroke which can cause the hull to pitch. Sliding rigger systems are banned in formal races.

Sliding seat/rigger systems that include, in one unit, the seat, outriggers to hold the oar locks, rails for either the seat or the outriggers to roll on and foot braces are typically called “DROP-IN UNITS”. The unit can be detached from the boat, and the boat ‘converted’ to fixed seat rowing.

Sliding seat/rigger COMPONENT systems are custom made such that the various separate components (seat, outriggers, rails and foot braces) are independent and are stored in the boat.

If you intend to sleep in the boat AND you are considering a drop-in system, where will you store the drop-in unit while you are sleeping? The only solutions I’ve seen are to 1) design a custom component system in which the pieces can be separately stored and/or are a built-in part of the boat, OR 2) only use fixed seat rowing.😊

If you are looking for parts to make your own system, then one source is Latanzo.

Following is a wide variety of sliding seat/rigger options, divided into three categories:
1) Plans and Kits
2) Commercial systems
3) Custom made systems, both component and drop-in

Plans and Kits


Glen-L
Glen-L Sliding Seat System

 Glen-L has both plans and a hardware (only) kit for this system.

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Colin Angus sells both plans and a kit for this sliding seat unit that he uses in his boats.

Colon Angus Sliding Seat System

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Platt Monfort’s article contains plans for a  home-made drop-in sliding seat system based on a 1947 design, with ‘upgrades’ provided by Platt.

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Kudzu Craft sells (only) the plans for this drop-in unit which can be customized to fit most boats.

Kudzu Craft Sliding Seat from Plans

Commercial Systems


Drop-in Sliding Rigger

Drop-in Sliding Rigger Unit from "Sliding Rigger"

Shown above is the end view and side view of their system. Note the very low profile, which would require the whole system to be raised in order to clear the gunnels of a typical oar cruiser.

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Adirondack Rowing has a review of seven commercial drop-in sliding seat units which they sell.

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Wayland Marine

RowWing by Piantedosi sold by Wayland Marine

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Poseidon sliding seat system

Double Seat version showing only Foot Rests for the Forward Seat

Both a single and double version are available, and either system can be fully adjusted to fit rowers up to 6’ 6”.

The system can be mounted in virtually any boat because it is supported by two crossbars attached to ribs

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Salt Pond Rowing


Wood Drop-in Sliding Seat Unit from "Salt Pond Rowing"

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FrontRower(TM) is not a sliding seat nor sliding rigger system, but a rowing system that enables legs and/or arms to be used to row, while facing forward.

Custom Made Systems


Gig Harbor custom component system they use in their boats.

Example of a Wood Sliding Seat System from "Gig Harbor"

They sell units with both wood (as here) as well as fiberglass seats. Eight wheels keep the seat located properly (See Rick Thompson's comments below.)

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Clovelly Sculls


Custom Component Sliding Rigger System for Their Boat

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Home Made Sliding Seat System

I found this photo of a home-made, drop-in, sliding seat (only) unit.  The dowel under the seat runs through a piece of PVC pipe to limit movement only to fore and aft. There was no ‘builder’ information.

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Custom (?) Drop-in Sliding Seat System

No builder information available.

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Rick Thompson, (Welsford custom Walkabout, shown here) wrote to me describing his custom designed component sliding seat system. He included many pictures. Following is the text and pictures he sent me:

"1) Many slide seats use 4 wheels held in tracks. The problem with those is that the wheel edges rub on the sides of the tracks, that's how they stay in the tracks. The wheels need to be a hard material, sometimes metal, which can cause a rough and noisy ride. 
2) My first open water rowing boat (that got me started on this activity) was a Gig Harbor Whitehall. Gig Harbor [See Gig Harbor link earlier in this post] has a seat system that uses 8 wheels - 4 supporting the seat and 4 keeping it on the flat top track. I like this system, mine is copied and revised from that. The GH wheels are soft urethane, making for a very smooth slide. The seat is securely held, it would have to jump up above the side wheels to come off track. The 4 wheel systems can jump track easier, unless there is also an upper retaining track. 
3) My GH boat and the Walkabout have side seats, making a convenient place to run the tracks. The Walkabout side seats curve upward at bow and stern, I just made my tracks to follow the curve and the slide seat works fine. The seat can easily be lifted out to make the center of the boat clear. The drop in seat units like Piantedosi or Angus can be added to boats with no side seat, but they are not quick to remove. 
4) If you look at the "Wheel Detail" tab on the GH page, you can see that they make their own wheel bearings from plastic parts. I have heard that these work well and have crossed oceans. I used standard skate board wheels and bearings which are readily available. The bearings can be found in stainless and even in ceramic. I used stainless, but re-packed them with heavy waterproof marine grade wheel bearing grease. They have not needed any service in over 2000 saltwater miles so far. 
5) My gray rafting seat is a little unusual. I have it angled backward by 12 degrees to better accommodate slide rowing geometry. It is very comfortable, even for a week of extended cruising. The low back part could interfere with layback, but I don't use much layback [for the ‘catch’] so it is not a problem.

[I asked Rick for the source of the seat he uses.]

This is what he uses.

Seat Rick Thompson Uses 

Underside of the Seat Showing the Eight Rollers to Keep it Aligned

Foot Rests of the Custom Component System

And a Close-up View

The Hinged 'Stop' Quickly Converts His Rig to a Fixed Seat Rig (Genius!)

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(Previously posted May 27, 2016)
Earlier this week, we posted a number of alternative sliding seat/rigger systems. Here are five more.

Fyne Boat Kits in UK offers this sliding seat system:

Sliding Seat System from Fyne Boat Kits

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Denman Marine in Tasmania offers this sliding seat system:

Denman Marine Sliding Seat System

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RowSurfer, located in Amsterdam, offers this sliding RIGGER system (seat is stationary and oar locks slide):


RowSurfer's Sliding Rigger System

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X-Cat , located in Austria, offers in interesting forward-facing, sliding seat system with automatic feathering. Shown is the rowing system (which can be purchased separately) mounted on their catamaran rower. See a video of the X-Cat in action.

X-Cat Forward Facing Sliding Seat System

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OarBoard, from Victoria, offer a sliding rigger system designed for SUPs (Stand-Up-Paddle). It could be adapted to oar cruisers.

OarBoard's Sliding Rigger System


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Thanks to Justin Miller and Rick Thompson for identifying these additional commercial sliding seat systems.

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(Previously posted June 23, 2016)

In the May 20 and May 27, 2016 posts, we presented a number of sliding seat/rigger systems. Here's another sliding rigger (seat is stationary while the locks and outriggers slide) that a reader sent me. No details except the photo.

 

Sunday, October 29, 2017

Rowing Geometry

(Note: This is a series of posts originally published 2016 each focused on a different aspect of powering small boats with oars. So far, we have re-posted the following topics:
  • Designs for various oars, including how to determine oar length... Sept 24
  • How to make a set of spoon-blade oars... Oct 1
  • The various ways to connect the oars to the boat... Oct 8
  • Alternative outriggers... moving the oar locks to a proper 'span' on a narrow hull...Oct 15
  • Various foot braces... Oct 22
  • This week, rowing geometry
  • And next week, sliding seat options

This post is about rowing geometry for fixed seat rowing.

Colin Angus has a very complete description, with detailed measurements, of rowing geometry for sliding seat rowing.

John Welsford, in an article for Duckworks Magizine titled "Some Thoughts on Rowing" includes the following information for rowing geometry for fixed seat rowing (as well as much more excellent advice):
  • Distance between oar locks: Minimum of 3’ 10” (117cm), and an average of 4’ (122cm) to 4’ 4” (132cm)
  • Oar lock to back edge of seat: Minimum of 13” (33cm)
  • Bottom of oar lock height above seat: 8” (20cm) to as high as 11” (28cm)
  • Seat height above ‘heel rest’ on foot brace: 6” to 8” (15cm to 20cm)

Paul Truszkowski’s rowing geometry for his Michalak Vireo is:
  • Distance between oar locks: 49.5:, 126cm
  • Oar lock to back edge of seat: 13”, 33cm
  • Bottom of oar lock height above seat: 12.5”, 32cm
  • Seat height above ‘heel rest’ on foot brace: 8”, 20cm
  • Bottom of oar lock to waterline: 13.5”, 34cm
  • Length of oars: 96”, 244cm
  • Overlap when oars are level: 4”, 10cm
  • Paul's height with shoes he normally wears when rowing. 6’ 1”, 185cm

Rowing Geometry for my own Ross Lillistone Flint is: (Note: this link works as of October 2017 but may change as Duckworks site is upgraded)
  • Distance between oar locks: 53”, 134cm
  • Oar lock to back edge of seat: 10”, 25cm. The oar locks are closer to the seat because I like to make a deeper recovery (forward angle of oars at the catch: 50 degrees) and shorten the end of the power stroke (35-40 degrees aft)
  • Bottom of oar lock height above seat: 10”, 25cm
  • Seat height above ‘heel rest’ on foot brace: 10”, 25cm
  • Bottom of oar lock to waterline: 14.5”, 37cm
  • Length of oars: 96”, 244cm
  • Overlap when oars are level: 3”, 76mm
  • My height with shoes I normally wear when rowing: 6’ 1”, 185cm

An effective ‘rule of thumb’ for adjusting the foot brace is to sit on the seat in your normal rowing position, extend your legs until your thighs are level, then position the foot brace against the bottom of your feet.


Pictured below is a Rowing Geometry Worksheet you can download from Dropbox and then ‘model’ your own rowing geometry based on you, the size of your boat and the length of the oars.

A Rowing Geometry Worksheet you can Download and Use

Sunday, October 22, 2017

Foot Braces

(Note: This is a series of posts originally published 2016 focused on a different aspect of powering small boats with oars. So far, we have re-posted the following topics:
  • Designs for various oars, including how to determine oar length... Sept 24
  • How to make a set of spoon-blade oars... Oct 1
  • The various ways to connect the oars to the boat... Oct 8
  • Alternative outriggers... moving the oar locks to a proper 'span' on a narrow hull...Oct 15
  • This week, various foot braces... Oct 22
  • And next week, rowing geometry...The relationship of seat, oar locks and foot braces.
"Foot braces", aka “Foot stretchers”, “Foot risers”, and “Piggy pedestals” are used by both sliding seat and fixed seat rowers. They are the braces that keep you from sliding aft when you row. 

In terms of design, there are probably as many designs as there are rowers. Following are seven examples, in no particular order. 

 

Steve Chambers' SOF British Columbia Hubert Evans Handliner

Detail of the Foot Brace and Box Seat
1. Steve Chambers built a SOF British Columbia Hubert Evans 14’ 6” Handliner (4.4m), using a plywood floorboard with a center stiffener strip. Both the box seat and foot brace are grooved to sit over the stiffener strip. Steve says the rope loop (around the back of the box seat and threaded through the foot brace) works well as long as you put equal pressure on the two ends of the foot brace. Distance between the foot brace and the box seat is adjusted by the sliding knot (tautline hitch or rolling hitch?... latter is less likely to slip).

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Close up of the Foot Rest and Straps

Rick Thompson's Foot Braces

2. Rick Thomson made these foot braces for his Walkabout (Rick's Walkabout). As with all of Rick’s work, these are elegant and superbly made. Note that Rick uses these for both sliding seat (for racing) and fixed seat rowing. 

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3. John Welsford's design for the Walkabout specified a series of about 6 paired ribs (about 12mm square) attached to the side of the air boxes at the same location as Rick placed the notched supports for his foot braces. John’s ribs are angled back from the vertical about 30 degrees and are spaced about 12 to 14mm apart. The actual foot brace is a plank that slides into the slot between ribs. 


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Paul Truszkowski's Drop-in Rowing Unit, Integrating Seat, Foot Rest and Outriggers

The Rowing Unit in a Custom 15' 6" Kayak/Rowboat

4. Paul Truszkowski built a drop-in unit that combines foot brace, outriggers and a seat.   

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Adjustable Foot Brace Attached to Seat in a Michalak Verio

5. In Paul’s Vireo (referenced in this blog), the foot brace is attached to the seat by adjustable chains. I’ve used this and it works well. 

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6. In the model Vireo (pictured at the link above), another adjustable foot brace is shown. It is hooked into the slats of the floor boards, as is the box seat, to allow both to be adjusted for leg length and fore/aft weight distribution. 

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Adjustable Foot Brace for a Ross Lillistone Flint

Forward End of the Brace Held in Place by a Wedge

Underside of the Foot Brace

After End of the Brace Showing One of the Wing Nuts

7. For Ross Lillistone’s Flint, I made this adjustable foot brace. The forward end is held down by a wedge jammed under the block screwed to the bulkhead. Two wing nuts anchor the sliding foot brace on the slotted beam, providing a wide range of adjustment. (Note that the only fasteners used are the two wing nuts. All the other joints are held only by Titebond 3 which has held up for two seasons.)


What would I do differently in making this foot brace? 


a. Make the actual brace much taller. I find it more comfortable to have the ball of my foot supported by the brace in addition to the heel. In addition, I’d make the brace wider so that I could brace my feet better (wider) in rough conditions.  
b. Create a better way to secure the front end of the slotted beam. The wedge is just okay, but has a tendency to work loose. 
In the March 2016 issue of Small Boat Monthly, Ben Fuller wrote an article on foot braces, in which he shows 10 different designs of foot braces. With a total of 17 different designs, there should be a style that is suitable for your oar cruiser. 


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(Following was first posted May 2016)

In an earlier post on foot braces, we presented 7 different styles. Chris Partridge, in his blog, Rowing for Pleasure, introduces us to Jubilee, a 18' lapstrake Langstone Cutter.

18' Langstone Cutter Jubilee

Jubilee uses yet another style of foot brace.
Foot Brace in Jubilee

The line leads to the yoke on the rudder. Note also the beautiful, knot-free floor boards, riveted lapstrake planks and keelson.

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(Following was first posted February 2017)

In a July 2016 post, we presented Floorboard Alternatives. And frequently, for oar cruisers, we’ve recommended in this blog that floorboards be made from ‘slats’ arranged crosswise in order to provide adjustable anchor points for foot rests and a seat, and a dry sleeping platform.

This post is a description of floor boards and foot rests I made for my Ross Lillistone Flint.

My Ross Lillistone Flint, Raven

The slats in the floorboards are 1” by ½” (25mm by 13mm) Western Red Cedar. The two longitudinal struts (glued and screwed to every slat) are oak, ¾” x ¾” (19mm x 19mm).

The slats are spaced exactly ½” (13mm) apart to allow the cleats to hook under a slat.  The ends of every slat are tapered to the slope of the bottom. The floor boards (and foot rests) are finished in Exterior Watco Oil. Since there is a permanent rowing thwart, there was no need to make a separate, movable, rowing seat.


Floorboards Installed in Raven

I added a wedge to hold down the forward end of the floorboards to prevent them from lifting when pressure was applied to the foot rests. The wedge is jammed under a cleat used for the main sheet when sailing Flint.

Wedge to Hold Down Forward End of Floorboards

The footrests are made from 6mm Ocume, a single oak base (3/4” x 1.5” x 14” long: 19mm x 38mm x 356mm) and three aluminum cleats 3.5” (89mm) inches long, ¾” (19mm) high and ½” (13mm) deep. The three cleats are spaced so that they fit between and on either side of the longitudinal struts.


3 Aluminum Cleats to Hold the Foot Rests to the Floorboards

Foot Rests Locked to Floorboards

Back of the Foot Rests

The footrests and floorboards have worked very well. The footrests can be moved to any slat to accommodate different rowers or to adjust rowing geometry.

If I were to do it again, I’d make the struts (to which the slats are attached) bigger (deeper) to prevent the floorboards from bending up (slightly) when pressure is put on the foot rests. Other than that one change, I would use this arrangement in future rowing boats.

Questions and/or comments are welcome.


Sunday, October 15, 2017

Outrigger Options

(Note: This and the following posts were originally published in 2016... they each focus on a different aspect of powering small boats with oars. This post was published March, 2016.)

Following are examples of oarlock outriggers… some elegant and some not, but all do the job of providing spread to the oarlocks enabling the use of longer oars.

Selway-Fisher 15' Adirondack Guide Boat Outrigger
Outrigger on a Selway-Fisher 15’ Adirondack Guide Boat for David O' Dempsey. Note the thin metal plate on the outboard side of the gunnel that absorbs the torque of the rowing stroke. These outriggers fold 180 degrees to enable coming alongside docks and other boats.





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Custom Wayland Marine Merry Wherry Outriggers
Chris Duff, a long-distance ocean rower, had these outriggers built for his 19 foot “Northern Reach”, a modified Wayland Marine Merry Wherry.










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Monfort’s ‘wing’ outrigger is similar to many commercial outriggers. I would make the interior angle greater than his 60 degrees for fear of hitting my knuckles on the ‘catch’ portion of the stroke. I would also have a third bolt at the apex of the wing attached to a cross beam or the forward edge of the aft deck.






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Simple 'Hinge' Outrigger


















“RowerWet” uses this simple outrigger on a canoe as described in this "Instructables" article. I would be concerned about rowing torque either twisting the hinge and/or loosening the fastenings. Fastening a 3/8 or 1/2 inch triangle of plywood to the bottom of the hinge, with the base of the triangle (6 inches) a tight fit against the outside of the gunnel and the apex at the end of the hinge, would provide sufficient strength to prevent the twist from doing any damage.

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Model of Gavin Atkin's OarMouse Outriggers
Galvin Atkin’s OarMouse plans show another outrigger. Based on those plans, I made a model and here are photos of the outriggers. The outriggers slide under two vertical “L” shaped runners attached to the inside of the topsides as shown in this photo.












Side View of the Outrigger
This is a side view of the outrigger. The oarlock socket would be mounted on the upper right. The angle of the (white) top to the vertical slide accomodates the flare of the topsides.











Two Braces Support the Oarlock Platform


There are two braces to support the top of the outrigger.















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Outriggers that Slide on the Coaming and are Removable
These outriggers (from a model) hook onto the coaming. They can be slid on the coaming to make room for a passenger and/or to adjust the rower’s location for fore and aft balance.












End View of the Sliding Outrigger Model
This side view of the outrigger shows the ‘hook’ that goes under the inner strut on the coaming.












There is no single best outrigger… they each have their pluses and minuses. Hopefully, these samples will give you ideas on how you can make outriggers for your oar cruiser.
In the next blog, we'll introduce another New Jersey rowing venue.