8' Portland Yawlboat
The traditional yawlboat is a hard-working boat, carried on the stern davits of a larger working vessel.
They have sweet shapes to be easily driven and as was befitting the pride of workmanship that went into
|Design Number 148|
This latter day version is much lighter and smaller in size. She will make a splendid small tender for a
larger yacht and a fun small sailing dinghy for kids of all ages. She is light enough to be carried on
cartop racks or hung off the stern of a modest size cruiser, or lifted aboard and carried on deck.
Her beamy shape gives her good stability. She will row, tow, and sail well. The skeg aft provides directional
stability while rowing or towing. The slot designed into her skeg is there to provide a handhold, which will
help make her easy to lift.
An optional oarlock, aft, on the port quarter, will facilitate sculling. (Put it on either side to suit
yourself.) She has two oarlock positions on the gunwales. Depending on how she's loaded, the person rowing
can sit amidships or forward. Or, two sets of oars can be used for towing operations or training the crew....
For some time, I've thought about designing a version of this boat with another strake of planking, two or
four inches in depth, added at the sheer. This would greatly increase her carrying capacity and usefulness
as a tender. This has been done and the details are on the full-size pattern set.
A traditional lapstrake
8' Portland Yawlboat built by Mike Kiefer
Construction alternatives that are practical, beyond those shown on the drawings in this chapter, are Airex®-cored
fiberglass (see 11' Oregon Peapod for an example) and cedar strips sheathed in
fiberglass cloth and epoxy resin.
John and James Guzzwell built a lovely example of this design. She is used as a tender to the cold-molded 37'
pilothouse cutter Corcovado of our design built by their father, John Guzzwell.
Don Maceys cold-molded 8 Portland Yawlboat nearing completion
|Length overall||8'-0"||2.44 m|
|Length datum waterline||7'-6"||2.29 m|
|Estimated structural weight||50-75 lbs.||23-34 kg.|
|Displacement, to DWL||240 lbs.||109 kg.|
|Displacement-length ratio||254|| |
|Sail area||36 sq. ft.||3.35 m2|
|Sail area-displacement ratio||14.91|| |
|Prismatic coefficient||.579|| |
|Pounds per inch immersion||93|| |
|Entrance half-angle||30°|| |
Note: The displacement numbers are calculated to the arbitrarily chosen DWL.
The calculated ratios of displacement-length and sail area-displacement will vary widely
depending on the loading of the vessel.