Cal Boats 34
Masthead Sloop · Fin keel, spade rudder · 1968–1975
A masthead sloop with a fin keel and spade rudder, favored by Jensen Marine founder Jack Jensen for personal cruising
Designed by C. William Lapworth, built by Jensen Marine.
- LOA
- Beam
- Draft (max)
- Displacement
- Ballast
- Hull type
- Fin w/spade Rudder
See her sail
The Cal Boats 34, on the water
The fleet's own footage — the truest look at how she really moves.
Footage from SheHelms Sailing
Is it for you?
Character
Where this design lands on the numbers a shopper trusts — read straight from her own ratios.
LivelyComfort 24Sea-kindly
CoastalCapsize 1.89Bluewater
LightD/L 241Heavy
EasygoingSA/D 18.0Powered-up
TenderBallast 39%Stiff
A capable cruiser that sits just inside the offshore line — coastal work with real passages in her.
The living fleet
Sailed by the fleet
Where the fleet has filmed this boat.
Seen once across one channel of the fleet.
The record
Full specifications
The complete reference set — tap any figure to switch between metric and imperial.
Dimensions
Weights
Ballast / displacement
39.5%
Rig & sail area
Rig
Masthead Sloop
Ratios
SA / displacement
18.0
Displacement / length
241.3
Comfort ratio
24.3
Capsize screening
1.89
Hull speed
6.8 kn
Pounds / inch immersion
929
Hull
Hull type
Fin w/spade rudder
Construction
Fiberglass
Ballast type
Lead
Production
Years built
1968–1975
Units built
347
Designer
C. William Lapworth
Builder
Jensen Marine, Cal Boats
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.
Hunter Marine 339.96 mSame hull family0.2 m shorterA 1977 masthead sloop with a 38% ballast ratio, designed for stability and coastal performance
Islander 329.91 mSame hull family0.2 m shorterA J.H. McGlasson-designed masthead sloop that served as the foundational hull for the later Islander 33 and 34 models
Moody 34610.52 mSame hull family0.4 m longerA 10.5-metre masthead sloop with a 40% ballast ratio, offering a stable and comfortable platform for coastal cruising
Contessa 329.75 mSame hull family0.4 m shorterA 1973 London Boat Show winner with a skeg-hung rudder and a ballast-to-displacement ratio of 47 percent
Seidelmann Yachts 3410.36 mSame hull family0.2 m longerA 1981 masthead sloop with a 45% ballast ratio, balancing a light-displacement hull with a deep 1.65-meter fin keel
Dehler Yachts 3410.10 mSame hull familyNear-identical lengthAn IOR 3/4 ton racer-cruiser designed by Van de Stadt, offering a balanced performance pedigree in a comfortable hull
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.
Cal Boats 34-IIIA late-seventies evolution of the original hull, updated with an offshore-oriented interior for blue water cruisingCal 2-34A high-aspect masthead sloop built for two years to optimize the original hull for IOR rating performanceCal Boats 24The inaugural Jensen Marine Cal model, this fractional keel-centerboard sloop was built for shoal-water versatilityCal Boats 43A rare, short-lived production model from 1971 featuring a masthead rig and a performance-oriented fin keelCal Boats 40A legendary offshore racer with 160 built, featuring a light displacement and a high sail-area-to-displacement ratio
Keep asking
The fleet has more to say
Search what's been said about the Cal Boats 34, or ask a specific question — the answer comes back written out, with links to the moments it draws on.
The newsletter
New boats, new stories, from everywhere.
One email from the fleet — boats newly added, videos newly analyzed. No noise.