Mark Smaalders Yacht Designs

Designs for seaworthy, affordable cruising boats -- specializing in wood/epoxy construction


 

On the Drawing Board

Work has been slower than expected on these designs, but if you've been waiting for Kahuna Nui or Simplicity, don't give up. Send an email if you have questions on any of these, or would be interested in a modified version of one of my stock plans.


Sea Lion: a steam launch
Here's something different: a steam powered tug-style cruiser, measuring 32' x 8' x 3'3". She sports a 30" prop, and would also be suitable for a slow turning diesel if you're not a steam buff. The biggest surprise is that she's trailerable. The hull will have a strip planked core topped by two layers of 1/4" ply set at 45º.


Wynfall MKII
A modifed version of the original, with standing headroom. A four-berth interior, enclosed head ..... a lot of boat for 26.5'.

 

Kahuna Nui: an enlarged version
I've had several requests for a larger version of Kahuna. Here's one version that's in the computer, measuring 38' on deck, with a beam just over 12' and some hollow in the underwater lines. Another is slightly longer and slimmer, with a hull form that's unchanged from the current Kahuna. In either case, she'll be available with a choice of rigs, and several construction options.
 
 

 

DeepSea37 Profile
Deep Sea 37: a wineglass cutter
This design began as a sketch for Practical Boatowner's Deep Sea Forum. She's substantial: 37' on deck, with a beam of 12' and a draft of 6', she'll displace about 20,000 lbs. With a wineglass hull she'll be more of a challenge to build than my other designs, but she'll be a powerful sailing boat, very much at home offshore. She'll be offered with a cutter rig (in both gaff and bermudan versions).

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Simplicity: a robust ocean cruiser

This double-ender is intended to be a simple, practical and reliable ocean cruising boat. Watertight bulkheads fore and aft make her effectively unsinkable. Simplicity is intended as a comfortable liveaboard/long-distance cruising boat, which gives maximum space and comfort for minimum investment and labor. The boat's major features all stem her shoal draft: that has dictated the rig (center of effort as low as possible); the hull form (maximum form stability but sufficient depth and displacement to maintain good reserve stability); and the raised deck (important for both strength and stability).
 
Hull form is a simple modified v hull, with a flat center section (2.5' wide amidships, which tapers in width fore and aft); the chine between the bilge panels and topside panels is below the waterline for the entire length. There is a wide, shallow ballast keel that bolts to this flat, and on which the boat will sit when beached. Hull depth is 30", while overall draft at the skeg is 36". The centerboard shown is a simple, triangular shaped board, though a higher aspect foil would also be possible.

 
Simplicity particulars
LOA: 42'
LWL: 37.5'
Beam: 13'
Draft: 3'
Disp:  25,000 lbs,
Ballast: 8000 lbs
Disp/Length ratio: 211
Sail Area: 985 (Main. Mizzen, 100% FT)
SA/Disp ratio: 18.44
 
She features a raised deck to maximize on stability and interior/deck space, for strength, and for ease of construction. All hull panels are plywood, over plywood bulkheads and frames. Construction would be very straightforward, using the permanent bulkheads, frames and other interior fittings as molds. There is no chine log, but instead the joint is finished with epoxy coving and biaxial tape ("stitch and glue" style); all bulkheads and interior joinery would be secured in the same way. The deck is laminated plywood over fore and aft beams.
 
The rig shown (sorry that I can't get more of it in view) features fully battened, heavily roached sails that are laced to the masts; spars are hollow spruce. The spars are designed to need little support from the rigging. Battens are easily fashioned from PVC and douglas fir, and lacing the sails to the masts eliminates any problems with raising and lowering the sail, making expensive luff hardware unnecessary.
 
Power required would be about 35 hp, swinging a large 2 blade (or folding) prop.
 
The concept  is based loosely on designs by Ralph Munroe, who lived in Florida beginning in the 1880's. He produced a series of very able, fast, shoal draft boats, the most famous of which was the Presto. Also among his designs were the 52' shoal draft cruising yachts Carib and Alice.


The layout shown is just one example of what would be possible in the hull -- she's roomy, with a wide cabin sole, so there's considerable flexibility in arrangement.