BoatsSeagull 18

Seagull 18

Masthead Sloop · Keel/centreboard · First built 1956

An Ian Proctor-designed masthead sloop offered as a kit by Bell Woodworking, featuring a versatile keel-centerboard hull

Designed by Ian Proctor, built by Bell Woodworking.

LOA
Beam
Draft (max)
Displacement
Ballast
Hull type
Keel/Cbrd.

Is it for you?

Character

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

TrailerableBeam 2.06 m — inside the 2.55 m no-permit tow width across most of Europe, and the 2.59 m US and Canadian limit. About 762 kg of hull, so roughly 1,350 kg on a trailer: check that against your own towing rating.Ramp-launchableAbout 762 kg of hull, with a keel that raises or a draft shallow enough to float off a trailer — she can go back on the trailer at the ramp, not only into the water.Shoal draftDraws 0.43 m, board up where she has one — creeks, sandbars and thin anchorages most keels have to stay out of.
LivelySea-kindly

Her light displacement on a beamy beam gives 12 — a quick, lively motion that feels every wave.

Comfort ratio 12
CoastalBluewater

2.27 — right around the 2.0 line, the edge between coastal and offshore.

Capsize screening 2.27
LightHeavy

146 — light for her waterline, so she is easily driven and quick to accelerate.

Displacement / length 146
EasygoingPowered-up

24.4 — a lot of sail for her weight; powered-up and eager, a real performer.

Sail area / displacement 24.4
TenderStiff

21% of her weight is ballast — on the tender side; she'll heel readily and want a reef sooner.

Ballast 21%

Light and lively — happiest day-sailing and coastal-hopping in settled weather.

  • Narrower than ~77% of boats her size on file

Compared with 440 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
20.8%
Rig & sail area
Rig
Masthead Sloop
Ratios
SA / displacement
24.4
Displacement / length
146.1
Comfort ratio
11.6
Capsize screening
2.27
Hull speed
5.6 kn
Pounds / inch immersion
416
Hull
Hull type
Keel/Cbrd.
Construction
plywood, hard chine
Production
Years built
First built 1956
Units built
400
Designer
Ian Proctor
Builder
Bell Woodworking

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.

Dufour Yachts T66.15 mSame hull family0.5 m longerA lightweight 800kg fractional sloop with a high sail-area-to-displacement ratio for spirited performance in light air
O'day 226.61 mSame hull family1.0 m longerA prolific production success with over 3,000 hulls built, offering a nimble fractional rig for coastal daysailing
Marshall Marine Corporation Sanderling5.54 mSame hull familyNear-identical lengthA gaff-rigged catboat based on a 1941 design, featuring a shallow-draft keel-centerboard hull for versatile day sailing
Microtonner 195.50 mSame hull familyNear-identical lengthA high-performance fractional sloop designed by Nestor Volker to the International Micro Class rule for competitive racing
O'day 23-1 (Lift Top)7.01 mSame hull family1.4 m longerA popular C. Raymond Hunt-designed masthead sloop featuring a unique lift-top coach roof for added cabin headroom

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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