BoatsSwan 431

Swan 431

Masthead Sloop · Fin With Rudder On Skeg · 1976–1978

A Sparkman & Stephens masthead sloop featuring a skeg-hung rudder and a high ballast ratio for offshore stability

Designed by Sparkman & Stephens, built by Nautor.

LOA
Beam
Draft (max)
Displacement
Ballast
Hull type
Fin With Rudder On Skeg

See her sail

The Swan 431, on the water

The fleet's own footage — the truest look at how she really moves.

Footage from SEILmagasinet

Is it for you?

Character

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

LivelySea-kindly

Her heavy displacement on a moderate beam gives 36 — a sea-kindly motion in a seaway.

Comfort ratio 36
CoastalBluewater

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

Capsize screening 1.80
LightHeavy

320 — heavy for her waterline, built to carry stores and ride steadily.

Displacement / length 320
EasygoingPowered-up

16.2 — moderate power for her weight; steady, all-round performance.

Sail area / displacement 16.2
TenderStiff

45% of her weight is ballast — stiff, standing up well to her sails.

Ballast 45%

A capable cruiser that sits just inside the offshore line — coastal work with real passages in her.

  • Heavier than ~83% of boats her size on file
  • Draws more than ~87% of boats her size on file
  • Beamier than ~76% of boats her size on file

Compared with 2563 boats of the same type within a quarter of her length.

What the fleet has seen

The Swan 431, as the fleet has seen it

Derived from the videos the fleet has analysed of this model. ▶ marks open the moment aboard.

The Swan 431 is a Sparkman & Stephens-designed masthead sloop built by Nautor from 1976 to 1978. It features a fin keel with a rudder on a skeg, measures 13.2 meters LOA with a 4.1-meter beam, and draws 2.3 meters. The displacement is 12020 kg. The design, S&S 2238-C1, has a sail area to displacement ratio of 16.2 and a comfort ratio of 35.5.

The living fleet

Sailed by the fleet

Where the fleet has filmed this boat.

Basemap © Wikimedia Commons · CC BY-SA 4.0

The record

Full specifications

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

Dimensions
Weights
Ballast / displacement
44.9%
Rig & sail area
Rig
Masthead Sloop
Ratios
SA / displacement
16.2
Displacement / length
319.5
Comfort ratio
35.5
Capsize screening
1.80
Hull speed
7.7 kn
Pounds / inch immersion
1597
Hull
Hull type
Fin with rudder on skeg
Construction
Fiberglass
Ballast type
Lead
Production
Years built
1976–1978
Units built
32
Designer
Sparkman, Stephens
Builder
Nautor

Boats like this, on the water

More boats like her, on the water

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.

Hallberg-Rassy 42 (Frers)13.22 mSame hull familyNear-identical lengthA German Frers-designed masthead sloop built for blue-water cruising, featuring a stable fin keel and a 181-unit production run.
Hallberg Rassy 42 - Behind the Curtainfrom Practical Sailor
Malo Yachts 4213.15 mSame hull familyNear-identical lengthA 13-metre blue-water cruiser with a 40% ballast ratio, built for over a decade to provide a stiff and predictable motion
[OFF MARKET] Malo 42 (GALADRIEL) - Yacht for Sale - Berthon International Yacht Brokers0:09from Berthon International
Bowman Yachts 4213.13 mSame hull familyNear-identical lengthA 13-metre cutter by Chuck Paine featuring a skeg-hung rudder and a balanced sail area-to-displacement ratio
Bowman 40 - A Survey & Sea Trialfrom Hold Fast!
Nicholson 4413.18 mSame hull familyNear-identical lengthAn extended Nicholson 42 featuring a modified deck molding that creates a convenient walk-through to the aft cabin
Camper and Nicholson 44 - A Yacht Delivery from Falmouth to Gosport0:34from Halcyon Yachts - International Yacht Delivery
Columbia 4313.18 mSame hull familyNear-identical lengthA William Tripp Jr. design featuring a high ballast ratio and a masthead rig, built for offshore performance
Felipe from Velejar Brasil | #SAL #10414:21from Hashtag Sal
Tanton 4313.16 mSame hull familyNear-identical lengthA versatile 13-meter cruiser also marketed as the Offshore and Explorer 43, available in both standard and pilothouse
Watch if you want to change your life | #SAL #13110:26from Hashtag Sal

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.

Swan 41A Sparkman & Stephens masthead sloop designed for offshore stability with a high comfort ratio and skeg-mounted rudderSwan 411A Sparkman & Stephens masthead sloop developed from the Swan 41, featuring a deep-draft fin keel and skeg-hung rudderSwan 57 S&SA Sparkman & Stephens masthead sloop designed for blue-water cruising with a heavy, stable displacement hullSwan 371A Ron Holland-designed masthead sloop built by Swan, balancing a stiff fin-keel hull with a comfortable cruising layout

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The fleet has more to say

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