BoatsJ Boats J/121

J Boats J/121

Fractional Sloop · Fin w/bulb & Spade Rudder · First built 2018

A high-performance fractional sloop featuring a water ballast system that adds 867 lbs of stability for shorthanded sailing

Designed by Alan Johnstone.

LOA
Beam
Draft (max)
Displacement
Ballast
Hull type
Fin w/bulb & Spade Rudder

Is it for you?

Character

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

LivelySea-kindly

Her light displacement on a moderate beam gives 18 — a quick, lively motion that feels every wave.

Comfort ratio 18
CoastalBluewater

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

Capsize screening 2.16
LightHeavy

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

Displacement / length 116
EasygoingPowered-up

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

Sail area / displacement 24.9
TenderStiff

40% of her weight is ballast — moderately stiff, a middle-of-the-road stability.

Ballast 40%

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

  • Draws more than ~94% of boats her size on file

Compared with 2742 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
40.3%
Rig & sail area
Rig
Fractional Sloop
Ratios
SA / displacement
24.9
Displacement / length
116.0
Comfort ratio
17.6
Capsize screening
2.16
Hull speed
8.0 kn
Pounds / inch immersion
1573
Hull
Hull type
Fin w/bulb & spade rudder
Construction
Infused FG/Epoxy with balsa core.
Ballast type
Lead Bulb
Production
Years built
First built 2018
Designer
Alan Johnstone
Builder
J 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.

Pogo 4012.18 mSame hull familyNear-identical lengthA pioneering Class 40 racer with a 3-metre draft and a 4,800kg displacement designed for high-speed offshore competition
Blue Jacket 4012.14 mSame hull familyNear-identical lengthA performance-oriented fractional sloop with a high sail area-to-displacement ratio, designed for speed and agility
Elan Marine 41012.27 mSame hull familyNear-identical lengthA 12.27-meter performance cruiser with a 2.2-meter draft and a high sail-area-to-displacement ratio of 20.52
Jeanneau Sun Odyssey 4012.20 mSame hull familyNear-identical lengthA 12.2-metre masthead sloop with a high sail area-to-displacement ratio, designed for spirited performance cruising
Scanmar 4012.24 mSame hull familyNear-identical lengthA masthead sloop with a 46% ballast ratio, engineered for stiff, high-performance offshore passage making
Jeanneau Sun Odyssey 40.312.20 mSame hull familyNear-identical lengthA 12.2-meter masthead sloop featuring a 1.95-meter fin-and-bulb keel designed for stable, mid-2000s cruising

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

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