Fatty Knees

Description

The Fatty Knees is a compact, classic fiberglass sailing dinghy designed by renowned naval architect Lyle Hess in the early 1970s, primarily as a versatile yacht tender that excels in rowing, towing, and sailing. Built by Edey & Duff in Mattapoisett, Massachusetts, from the 1970s through 2009 (and revived by Fatty Knees Boat Co. in 2010s), it comes in three sizes: 7 ft (2.1 m), 8 ft (2.4 m), and 9 ft (2.7 m), with the 8 ft model (4 ft beam, ~100 lb. / 45 kg) being the most popular. Featuring a lapstrake-style hull for strength and aesthetics, a kick-up rudder, daggerboard, and ~50 ft² sail area (fractional sloop rig), it's renowned for stability (carries 2–3 adults), ease of handling, and planning potential in light winds—reaching 5–7 knots. Ideal for yacht tenders or standalone daysailers, it's hand-laid with marine plywood reinforcements and teak accents, accommodating a 2 hp outboard. Only ~200–300 units were produced, making it a collectible "New England tradition" for coastal gunkholing or beach launches.

Custom sail calculations are not possible for this boat as no I, J, P and E dimensions are available.

Construction Details

Designer Lyle Hess
Builder Edey & Duff
Length 8.000 ft
LOA 9.000 ft
Beam 4.250 ft
Displacement 128 lb
Max Draft 3.250 ft
Min Draft 0.160 ft
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The standard boat dimensions

i -
j -
p -
e -
p2 -
e2 -
i2 -
j2 -

Sails

Sail Type MAINSAIL
Luff 11 ft - (3353 mm)
Foot 7.25 ft - (2210 mm)
Leech * 12.4 ft - (3780 mm)
Tack Angle * 84.49 °
Diagonal 12.58 ft - (3834 mm)
Head (inches) * 3.5 in - (89 mm)
Area * 41.12 ft²

Disclaimer. Boats are not all the same -- even when produced in the same factory of the same model. Sailrite does its best to publish accurate dimensions, but we often find it worthwhile to have our customers measure their boats carefully before we produce kits for them. You should take the same precautions, especially when the data is not from Sailrite. The information on this site is not guaranteed to be accurate. Sailrite offers this content as a service to our community, but takes no responsibility for the reliability of the data provided.