Mark Smaalders Yacht Designs

Designs for seaworthy, affordable cruising boats, sail and power
Specializing in wood and wood/epoxy construction

Simplicity 35
Simplicity 35

Simplicity is a simple, practical and reliable ocean cruising boat. Simplicity is intended as a comfortable liveaboard or long-distance cruising boat, which gives maximum space and comfort for minimum investment and labor. The boat's major features all stem from 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).
The hull form is a simple modified v hull, with a flat center section (2.5' wide amidships, which tapers in width fore and aft). There is a wide, shallow ballast keel that bolts to this flat, and on which the boat will sit when beached. Overall draft is just over 2' with board up, and 5.6' with board down.


LOA (includes bowsprit & rudder)

 41'  9"

Long. Center of Buoyancy

18.13’ aft


Length on deck

35’ – 3”

Center of Gravity

.25’ above DWL




Prismatic Coeff.




11’ – 3/4”

Pounds/inch imm.



Beam at WL

10’ – 5”

Dellenbaugh Angle

9.17 (stiff)

Draft (cb up)

2’ – 3/4”

Wind pressure coeff.

1.60 (stiff)


Draft (cb down)

5’ – 8 1/8”

Moment to trim 1”

1022 lbs



15,350 lbs

Wetted surface

253 ft²




Maximum righting moment

38519 ft lbs at 66 degrees


Ballast/Disp. ratio


Limit of positive stability (hull only)

128 degrees


Sail Area

644 ft²

Tankage (water)



Sail Area / Disp.

16.75 (gaff rig, working sail)






Disp. / Length


All hull panels are plywood, over plywood bulkheads and frames. Construction is straightforward, using the permanent bulkheads, frames and other interior fittings as molds. Builders have the option of using a traditional chine or using epoxy coving and biaxial tape ("liquid joinery" style); bulkheads and interior joinery can also be secured with cleats or epoxy and tape. The deck is laminated plywood over a combination of fore and aft beams and athwartship beams.
Power will be about 25 hp, swinging a folding prop.  

In addition to the gaff rig, she'll also be offered with a Simplicity rig, which is still under development. It features a fully battened, heavily roached mainsail laced to the mast; the mast is hollow, and designed to need little support from the rigging. Battens are easily fashioned from PVC, and lacing the sails to the masts eliminates any problems with raising and lowering the sail, making expensive luff hardware unnecessary. A sailplan for the Simplicity 42 is below; the 35 would be similar.

Simplicity Rig (shown here on the Simplicity 42)


S35 Layout

S 35 Layout and Inboard Profile