BoatsKnockabout 24 (S&S)

Knockabout 24 (S&S)

Masthead Sloop · Fin Keel · First built 1962

A cabinless Sparkman & Stephens masthead sloop designed for training at the Annapolis Sailing School and Naval Academy

Designed by Sparkman & Stephens, built by Tidewater Boats.

LOA
Beam
Draft (max)
Displacement
Ballast
Hull type
Fin Keel

Is it for you?

Character

Where this design lands on the numbers a shopper trusts — read straight from her own ratios.

TrailerableBeam 1.91 m — inside the 2.55 m no-permit tow width across most of Europe, and the 2.59 m US and Canadian limit. About 1,021 kg of hull, so roughly 1,600 kg on a trailer: check that against your own towing rating.Shoal draftDraws 1.07 m, board up where she has one — creeks, sandbars and thin anchorages most keels have to stay out of.
LivelySea-kindly

Her moderate displacement on a narrow beam gives 16 — a quick, lively motion that feels every wave.

Comfort ratio 16
CoastalBluewater

1.91 — just under the 2.0 offshore line; her beam is modest for her weight.

Capsize screening 1.91
LightHeavy

196 — moderately heavy for her waterline, a balanced cruising weight.

Displacement / length 196
EasygoingPowered-up

20.0 — plenty of sail for her weight; lively and quick to respond.

Sail area / displacement 20.0
TenderStiff

50% of her weight is ballast — stiff, standing up well to her sails.

Ballast 50%

Powered-up and quick to accelerate — this one likes to sail.

  • Lighter than ~88% of boats her size on file
  • Draws less than ~79% of boats her size on file
  • Narrower than ~98% of boats her size on file

Compared with 1398 boats of the same type within a quarter of her length.

The record

Full specifications

The complete reference set — tap any figure to switch between metric and imperial.

Dimensions
Weights
Ballast / displacement
49.8%
Rig & sail area
Rig
Masthead Sloop
Ratios
SA / displacement
20.0
Displacement / length
195.7
Comfort ratio
15.7
Capsize screening
1.91
Hull speed
5.6 kn
Pounds / inch immersion
385
Hull
Hull type
Fin Keel
Construction
Fiberglass
Production
Years built
First built 1962
Designer
Sparkman, Stephens
Builder
Tidewater Boats

Boats like this, on the water

Nobody has filmed this one — but these are close.

Comparable boats the fleet has on camera: same type, within a quarter of her length. Open the boat, or watch the video — a timestamp means she only appears in passing.

Halcyon 236.93 mSame hull family0.4 m shorterA triple-keeled masthead sloop by Alan H. Buchanan, offering shallow-draft versatility based on the earlier Crystal 23
J Boats Tillotson Pearson J/247.32 mSame hull familyNear-identical lengthThe world's most popular one-design keelboat, featuring a light 1406kg displacement for responsive, agile handling
J J/77.04 mSame hull family0.3 m shorterA 2024 fractional sloop with a shallow 1.16m draft and a high 23.55 sail-area-to-displacement ratio for responsive daysailing
Jeanneau Sun Odyssey 24.27.30 mSame hull familyNear-identical lengthA Jacques Fauroux-designed fractional sloop built for coastal cruising with a stable fin-and-bulb keel
Martinique 257.70 mSame hull family0.3 m longerA Brazilian-built masthead sloop with a 44% ballast ratio, offering a stiff and stable platform for coastal cruising
Sirius 7277.27 mSame hull familyNear-identical lengthA development of the Sirius 24, this fractional sloop features a fin keel with skeg-mounted rudder for balanced handling

The family

Related models

The designs closest to hers — usually the rest of the builder's range, sometimes the same hull sold under another name.

Keep looking

Nothing filmed of this one yet

Two ways to keep looking — both search what the fleet has actually recorded.

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