Mechanics & Energetics of Rowing

For those who are interested in the technical aspects of rowing, here is a link to a dissertation (in English) from Vrije University in the Netherlands. The dissertation focuses on the impact of various mechanical and human physical variables on rowing. The Summary, starting on page 142 provides an overview of the results found. Thanks to Mark G. of Ottawa for sending this to me.

This link is to Dropbox for the .pdf file, "Mechanics and Entergetics of Rowing".

Selway-Fisher's Medway Skiff

Selway-Fisher’s Medway Skiff Medway Skiff is a pretty little eleven foot rowing skiff that could be converted into a beautiful oar cruiser suitable for protected waters. The shortest boat we've considered that could be an Oar Cruiser. 

Selway-Fisher's Medway Skiff

She is very similar in concept to Bolger’s Cartopper… both offer a small, one-person oar-powered boat that, with suitable decking and collapsible shelter, would be comfortable for overnight or weekend mini-cruises.

Specifications: 

Length: 10' 9" (3.3 m)

Beam: 48": (1200 mm)

Weight: 75 pounds (34 kg)

Water Line Length: 9' 10" (3.0 m)

Water Line Width: 35" (884 mm)

WLL/WLW Ratio: 3.4:1

Hull  Speed: 4.2 knots, 7.8 kph, 4.8 mph

Plan Overview:

Medway Skiff Plans Overview

Plans available from Selway-Fisher.

Description by Selway-Fisher:

“The Medway 11 is a rowing skiff development of our Medway Doble design. We have retained the same 3 plywood planks per side and the simple stitch and tape method of construction. She uses just 3 sheets of 5 or 6mm plywood. As drawn, she is fitted out for single use with a central rowing thwart and with buoyancy/stowage compartments at either end. These can be replaced by seating so that she could take 3 adults. Her ‘V’ bottomed hull section has a moderate waterline beam keeping the wetted surface area to a minimum making her easy to row and straight tracking. She has a ‘wineglass’ shaped transom giving her some width at deck level with basically a double ended hull form at the waterline.” 

Conversion to an Oar Cruiser

• Add a set of cross-slatted floor boards that would span the V-bottom and be level fore and aft.
• Add a removable rowing seat and foot brace that would lock into the floor boards.
• Add two watertight compartments fore and aft to provide at least a 6.5' (1981 mm) long cockpit with access hatches either on the decks or the bulkheads.
• Because the permanent thwart would be eliminated, double the in-wales, with spacer blocks, to provide the stiffening of the hull that the thwart provides.
• Add a shelter to provide protection while sleeping.

Summary-Pros:

• Light enough to car-top.
• Easy to row at slow speeds.
• Capable of holding one person plus supplies for a week.
• Ideal for protected waters.

Summary-Cons:

• Limited displacement.
• Short WLL limits top speed.

Two Medway Oar Cruisers at Stockton Lake:

They had spent the winter building two 'his and her' Medway Oar Cruisers. Strapped together and riding on the roof rack of their SUV, they drove to Missouri and launched at one of three marinas on Stockton Lake. The lake has over 288 miles of shoreline. They took full advantage of the camp sites but 'stealth camped' some nights in their Oar Cruisers, enjoying the solitude and quiet, anchored in one of the many small coves. A week later, they returned home, refreshed and delighted with the hundreds of photos they took of the abundant wildlife at the lake.

Passenger Seats for Small Boats

Let’s say you want to bring a passenger with you in your boat. What does he or she sit on, other than a boat cushion? One option is the ‘stern seat’, using the transom as a backrest… like this:

Stern Seat in a Bolger Cartopper (Photo: GrapeViewPointBoatworks.com)

The problem is the weight being so far aft in the boat can ruin the trim of the boat unless the paddler or rower (with a second set of oar locks) is far forward.

The purpose of this post is to show a number of other passenger seats that can either be purchased (complete or in kit form), or used as ideas/prototypes for making your own.

You could, for example, use a folding “stadium seats” such as this one…

Folding 'Stadium' Seat from Amazon

…from Amazon.

Another similar option is Gander Mountain’s SitBacker Canoe Seat.

Gander Mountain SitBacker Canoe Seat

FrontRower sells this folding passenger seat…

FrontRower Passenger Seat

… made from Cherry wood and matches, in style, the FrontRower(TM) Rowing System.

Glynn Sirmans in Duckworks Magazine created a very comfortable looking passenger seat.

Glen Sirman's Custom Passenger Seat

Plans for Glen's Passenger Seat

Ken Simpson Plans offers free plans for a simply made folding passenger seat.

Ken Simpson's Folding Passenger Seat

Chesapeake Light Craft offers a cane seat ...

CLC's Cane Passenger Seat

…that is similar (identical?) to this cane seat from Fyne Boats who sell CLC products in the UK.

Fyne Boats Cane Passenger Seat

Fyne Boats also shows this ‘slatted seat’ in another of their boats.

A Slatted Seat in a Fyne Boat

If you need a passenger seat in your oar cruiser or canoe, I hope these alternatives will provide you with ideas on either purchasing a seat or building your own.

Shellback Dinghy

A pretty 12 foot dinghy…

Shellback Dinghy from Ballentine Boats

This Joel White Shellback Dinghy design is very similar to Bolger’s CarTopper. Both are about the same length and width. One difference is that CarTopper has two side panels and the Shellback has three. Both have a flat bottom.


Pictured below is an example built by Salt Pond Rowing used as the tender for a larger boat.

Rowing (only) Shellback Built in 2001

In the write-ups, there was praise for the Shellback as an excellent sailing, rowing and towing dinghy.

Shellback Dinghy Sailing...

...Rowing...

...Towed

Plans are available from the Wooden Boats Store

Plans from Wooden Boats Store

Specifications are

• LOA:11' 2" (3.4m) 
• Beam 4’ 5” (1.3m)
• Sail area is 54 Sq. Ft. (5 Sq. m)
• Displacement 125 lbs (57kg).

The optional sailing rig consists of a standing lug sail on spars that can be stored inside in the boat with a dagger board and rudder.





If we made the same changes as those for the Cartopper…

• Eliminate the sailing components (?)
• Add floor boards covering 7’ (2.1m) of the bottom
• Add fore- and aft-decks to minimize the size of the cockpit (to about 4’ [1.2m])
• Add a tent of some form for weather protection.

…then we would have another very pretty and compact single-handed oar cruiser.