Beta Marine

Beta Marine

Sailboat Specifications

Hull Type: Fin with rudder on skeg
Rigging Type: Masthead Sloop
LOA: 9.14 m
LWL: 8.21 m
S.A. (reported): 44.04 m²
Beam: 3.10 m
Displacement: 4,536 kg
Ballast: 2,087 kg
Max Draft: 1.62 m
Construction: FG
First Built: 1972
Builder: Irwin Yachts (USA)
Designer: Ted Irwin

KLSC Leaderboard

KLSC Leaderboard

Auxiliary Power/Tanks (orig. equip.)

Make: Universal
Model: Atomic 4
Type: Gas
Fuel: 76 L


Water: 189 L

Sailboat Calculations

S.A. / Displ.: 16.39
Bal. / Displ.: 46.00
Disp: / Len: 228.84
Comfort Ratio: 25.27
Capsize Screening Formula: 1.89
S#: 2.32
Hull Speed: 6.95 kn
Pounds/Inch Immersion: 978.23 pounds/inch

calculation mobile

2 nd ad half width

3rd ad full width

Rig and Sail Particulars

I: 12.71 m
J: 4.11 m
P: 10.67 m
E: 3.35 m
S.A. Fore: 26.15 m²
S.A. Main: 17.88 m²
S.A. Total (100% Fore + Main Triangles): 44.03 m²
S.A./Displ. (calc.): 16.39
Est. Forestay Length: 13.36 m

Sailboat Links

Designers: Ted Irwin
Builders: Irwin Yachts
Associations: Half Ton Class
Irwin Facebook Group
Irwin Yacht Owners
Download Boat Record:


IOR 1/2 ton based on IRWIN 30.
Shoal draft version also available.