|Hull draft||0.112m||0' 4⅜"|
|Draft (board down)||0.900m||2' 11⅜"|
|Bare hull weight||61kg||134lbs|
|All-up sailing weight||100kg||220lbs|
|Displacement on dwl||285kg||628lbs|
|Sinkage on dwl||39kg/cm||218lbs/in|
Design No. 181 – 4.745m (15'6¾") yawl-rigged skiff
The skiff is designed to be sailed and rowed. The yawl rig provides good control in a variety of conditions – we would expect the mizzen to be in use under most conditions. The standing lug mainsail is designed so the the Centre of Effort of the sail plan remains pretty constant when reefed.
Optional slatted side benches are shown on the plan; these sit on top of the aft deck and mid-thwart and have support struts going down to the chine log. Both the mid-thwart and the optional side benches are removable so that the cockpit can be a clear space if wished for camping out.
The hull is built from 6mm ply hull panels on four plywood bulkheads/frames, three of which are double thickness 6mm ply; the transom is made from three layers of 6mm ply. On the CNC files, there are 6mm locating holes so that to assemble the frames (and the transom) the parts are epoxy bonded together, with short lengths of dowel locating them correctly. We have used this method on many of our designs very successfully. With this hull, using the CNC cut frame components, a builder could easily assemble and bond together the three frames and the transom in one or two days.
The non-ply structures – hog, stem, chine pieces, gunwhale, rubbing strake, stem knee, centrecase blocks and buoyancy chamber stringers – are made from Douglas Fir or similar (the actual timber species is not particularly important). Most are simple rectangular profile; only the chine pieces and the buoyancy chamber stringers have bevel on them.
A complete General Arrangement Plan is available hereThe plan is a large PDF file and opens in a new window.. On this, the basic construction of the bulkheads and transom can be seen and also the forward and aft buoyancy compartments. These give a total volume of 0.283m3 (about 10 ft3).
Both main and mizzen masts are unstayed, constructed from Douglas Fir or similar. The main mast and main boom (which is rectangular section) can with advantage be made hollow. The mast from two halves hollowed out, or birdsmouth construction; the boom is box construction. It's not really worth making the main yard, the mizzen mast and mizzen boom hollow as the weight saving doesn't really justify the extra work. The bumpkin is laminated so that the mizzen passes through the heel of it, which secures the bumpkin in place.
Lift to windward is provided by the NACA 0010 series daggerboard which slides in a simple case. The rudder blade is a NACA 0009 series foil, pivoting up when beaching or in shallow water. The tiller hinges up about 40º and can be de-mounted easily.
The hull is put together on a very simple jig or strongback, to ensure accuracy.
For rowing, oars about 2.75m (9') long are suitable. The rowlocks (oarlocks) should be set into the gunwhale about 300mm (11¾") aft of the aft edge of the midships thwart.
A hull of this sort doesn't require a lot or power to move it, so a small (maximum 2.5kw/3 hp) outboard is sufficient. If an outboard is to be used, then an extra pad on the transom should be bonded on. Use of larger outboards is not recommended – the boat will likely dig her stern in and go nowhere fast!
Click here to look at the free study plans, sample instructions, specification and cutting list for this design, plus a full list of the plans and instructions that come with the design package.
CNC cutting files are available for this design.