13ft one person rowboat.

This is a boat optimised highly towards single person rowing at the expense of other capabilities.

At time of writing, October 2009 I have 3.5 sheets of high quality marine plywood in the backyard. Additionally I have 2 sets of oars from my larger dory, one set of which I could use for this boat.

This is a design I am contemplating for November of this year, 2009. This is in a response to rowing my 18ft dory. I have found that too large for single person rowing in a strong breeze due to high windage. Thus in response since I am considering a smaller rowing boat, designed only for one person. The design is low in freeboard and is not optimised for sailing.

The idea is for a rowboat that is to be used only in moderate conditions. It can survive more robust conditions if that eventuates. It is similar in appearance to some smaller banks dory, such as the South Haven light banks dory. However this boat is designed for greater speed at the expense of rough water capability. To optimise the design for speed as opposed to rough water capabilities, the stem and stern are much more vertical

Main features of this boat when compared to my previous 18ft dory are

• Greatly reduced windage
• reduced weight
• Easily car-toppable
• Easy to build
• Requires a small amount of materials
• Has greater initial stability for those less agile and for children
• Is optimised for one person, with ability to carry 2 at times
• Long waterline length for good speed
• Optimised for smooth water, with ability to survive moderate conditions if encountered

Some more features of this boat are

• Rowlocks are on outriggers to increase rowlock-rowlock separation
• A 4x2 timber is used to support the rowlocks
• Buoyancy compartments are fore and aft
• The thwart can be moved into one of two positions, for single and 2 person rowing
• The bottom panel is 66xm max width, which is 6cm wider than my present dory
• Midsection freeboard is 26cm at 140kg
• The top of the stem is 40cm above the waterline
• The rowlocks pivot out a few degrees to give the ideal angle. The axis of rotation is not vertical
• A skeg will need to be added, this is not shown in diagrams
• Rowboats are meant to have a narrow stern, this has a reasonably narrow stern

Because this is a one person recreational rowboat, and not a workboat, measures can be taken to optimise it for that use. This is done by enclosing off large bow and stern sections. If this was done in a work boat there would be no space to put fishing equipment. However this is not an issue in a small recreational rowboat. The use of a near vertical stem and stern results in a long waterline length that results in greater speed. The freeboard is low to reduce windage and allow for progress and control in a moderate wind.

This design has a great deal of similarity to Michael Storer's 15ft rowboat, Flint 14 by Ross Littingstone and the Whisp Rowboat by Steve Redmond.

It should be noted that this is not a balanced design. It is optimised for low cost construction, it is not designed with sailing in mind, and nor is it really optimised to carry other passengers, though this can be done, . If passengers are carried aft, then some water containers forward of the rowing position would be prudent for trim. The thwart can be moved forward a little to assist in trim. From experience I feel that a built in water ballast tank is the best way to go as opposed to removable water containers, maybe closer to the stem?.

Final Comment
Am I reinventing the wheel? Has this all been done previously. Does Gavin Atkin have something out there like this? I do not want to go to 15ft because I want to keep it small and easier to cartop. This design is created to have almost identical waterline length to my 18ft dory (due to large overhangs). this is where the 13ft length comes from

NEWS
I have changed the lines slightly in last couple of days. The new lines are at top, the earlier set are at bottom of page. The changes are more flare at the bow as per the boats of Atkins and co, more stern freeboard for better balance. I also levelled out the boat, this makes no difference in building but means that the diagrams make more sense.

Since I now am thinking of 55cm travel between 2 rowlock positions, I think I need two sets of outriggers, not the one as shown.

I have put the design file online for anyone to download it. You need to install the free hullform software from hullform.com to view the shape. The file can be downloaded from here

Here is an alternate thwart arrangement. Perhaps it is simpler lighter and more flexible than the first attempt.