The birth of an elegant 18′ sloop with shoal draft, recounted by Tony Dias:

Arey’s Pond Boat Yard is well known for the fine Catboats they produce. Tony Davis and I have wanted to work together for some time, and when this opportunity to build a sloop to fit in their line arose I jumped at the chance. Cape Cod is reknowned for its Cats, but there has also been a long tradition of handy, shoal sloops dating back at least a century. The Kingston Lobster Boat in Chappele’s American Small Sailing Craft while Cat Ketch rigged, is pretty close to being an ancestral working prototype.

These boats are beamy, although not as extreme as a Catboat, shoal draft, half decked with a graceful sheer and often a counter stern. I’ve always admired these craft and wanted to try my hand at one. I wanted to rethink the type in the light of current conceptions of aero- and hydrodynamics and contemporary developments in materials and construction techniques. Good design results from dealing directly with first principles, not tracing over what’s been done before.

The most glaring departure from tradition may be the rudder, more on that anon, but while the hull looks traditional; it is based on a family of hulls I’ve developed over the last few years. I’ve been looking for a hull form combining a high prismatic coefficient (in this case .56) with a moderate displacement. One with more deadrise than is currently fashionable. Carrying the rabbet line rather deep fore and aft of the midsection to spread out the volume longitudinally (hence the high prismatic) and using these vee-d sections to cushion the ride and dampen pitching moments. While this sort of hull won’t be as fast in flat water as an all out sled, it will be fast in a variety of conditions and will subject the crew to much lower G forces while slicing through rough water instead of crashing over it.

In this design, the deadrise is less evident than on others I’ve done and the beam to length ratio has been increased. This is a shallow hull with form stability instead of deep draft and ballast. I’ve maintained a long entry and hardened up the turn of the bilge. It’s important to minimize detrimental effects on trim caused by live weight. The half decked layout is ideal since it keeps the crew sitting where they will do the most good and out of the ends. Gear stowage and auxiliary power are also factors impinging on good trim. Net bags under the benches and sail stowage under the foredeck with fenders and docklines aft will help. A 2 hp four stroke, or an electric outboard, hung off a side mounted bracket can stow under a bench. The battery or fuel tank can sit just aft of the mast. One won’t be tempted to leave these motors hanging while under sail and they are light enough to be easily stowed and deployey.

The first of these boats will be built in strip/ composite construction with a combination of White Cedar and biaxial fiberglass cloth set in epoxy. A Mahogany veneer laid longitudinally, spiled like planking and sheathed in 10 oz. cloth goes over that. The deck is ply, covered in Dynel, and the backbone is laminated Douglas Fir. Subsequent boats will be molded in fiberglass and finished to Arey’s Pond’s normal high standards.

The rudder’s short blade benefits from an endplate with a swept sythe-like planform similar to a Tuna’s tail fin. It can generate strong lift even as it pitches and rolls. There is a slot between the rudder and the foiled skeg combined with a balanced blade – its shaft is aft of the leading edge a bit. The rudder acts like a slotted flap with cleaner flow, lower drag, and a higher stall angle.

I look forward to sharing photos and thoughts on the real boat even more than showing you the virtual one. Stay tuned!

By Tony Dias