BoatsSigma 38 (S&S)

Sigma 38 (S&S)

Masthead Sloop · Fin With Rudder On Skeg · First built 1967

A Sparkman & Stephens masthead sloop designed for offshore stability with a skeg-hung rudder and heavy displacement

Designed by Sparkman & Stephens, built by Cheoy Lee Shipyard Ltd.

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

See her sail

The Sigma 38 (S&S), on the water

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

Footage from Allende los Mares · Vuelta Vertical

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 narrow beam gives 43 — a heavy, notably soft motion offshore.

Comfort ratio 43
CoastalBluewater

At 1.54 she sits well under the 2.0 line — a solidly ocean-capable hull for her size.

Capsize screening 1.54
LightHeavy

408 — very heavy for her waterline, a serious load-carrying cruiser.

Displacement / length 408
EasygoingPowered-up

14.9 — modest power for her weight; easygoing rather than lively, and happier with a breeze.

Sail area / displacement 14.9
TenderStiff

35% of her weight is ballast — moderately stiff, a middle-of-the-road stability.

Ballast 35%

Built heavy and sea-kindly — a boat made to cross oceans and forgive a rough night.

  • Heavier than ~76% of boats her size on file
  • Narrower than ~82% of boats her size on file

Compared with 2900 boats of the same type within a quarter of her length.

What the fleet has seen

The Sigma 38 (S&S), as the fleet has seen it

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

The Sigma 38 (S&S) is a 11.7-meter masthead sloop designed by Sparkman & Stephens and built by Cheoy Lee Shipyard since 1967. It features a fin keel with a rudder on a skeg, a beam of 3.1 meters, a draft of 1.8 meters, and displaces 8629 kg. Aboard *Allende los Mares*, the Sigma 38 *Crobat* functions as a mobile research platform for the Sailing Living Lab project, testing marine technologies like Solar Face photovoltaic cells, an EasyWin ultrasonic anemometer, and an electronic anti-corrosion system.1:52 The vessel also tests aerial and underwater drones, a biomedical diving computer, TimeZero navigation software, and industrial radio controls adapted for winches. *Crobat* participates in collaborative sailing events and plans include a transatlantic crossing to the Caribbean.3:10

The living fleet

Sailed by the fleet

Where the fleet has filmed this boat.

Seen once across one channel of the fleet.

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
35.2%
Rig & sail area
Rig
Masthead Sloop
Ratios
SA / displacement
14.9
Displacement / length
408.4
Comfort ratio
43.1
Capsize screening
1.54
Hull speed
7.0 kn
Pounds / inch immersion
1007
Hull
Hull type
Fin with rudder on skeg
Construction
Fiberglass
Production
Years built
First built 1967
Designer
Sparkman, Stephens
Builder
Cheoy Lee Shipyard Ltd

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.

Warrior 3811.58 mSame hull familyNear-identical lengthA short-run 1980s cruiser featuring a shallow 1.52m draft and a heavy ballast-to-displacement ratio for steady offshore work
Aragosa Yachts 3811.61 mSame hull familyNear-identical lengthA 1988 masthead sloop with a 35% ballast ratio, designed by Ted Brewer for balanced offshore performance
Hallberg-Rassy 3811.57 mSame hull familyNear-identical lengthA 1970s masthead cruiser featuring a skeg-hung rudder and a substantial 43% ballast ratio for heavy-weather stability
Catalina Yachts 38011.71 mSame hull familyNear-identical lengthA 1997-era masthead sloop derived from the Morgan-Catalina 381, offering optional shoal draft and tall rig configurations
Morgan Yachts 38211.68 mSame hull familyNear-identical lengthA Ted Brewer-designed masthead sloop built for offshore stability, featuring a skeg-hung rudder and a stiff displacement
Catalina Yachts Morgan 3811.71 mSame hull familyNear-identical lengthA 1993-2005 production masthead sloop featuring a deep 1.98-meter draft and a performance-oriented fin keel

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.

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The fleet has more to say

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