Beta Marine

Sailboat Specifications

Hull Type: Long keel w/trans. hung rudder
Rigging Type: Gaffhead Sloop
LOA: 15.83 ft
LWL: 12.50 ft
S.A. (reported): 140.00 ft²
Beam: 5.83 ft
Displacement: 1,250.00 lb
Ballast: 735.00 lb
Max Draft: 2.50 ft
Construction: Wood
Ballast Type: Lead
First Built: 1914
Last Built: 1948
# Built: 400
Builder: Herreshoff Manufacturing Co.
Designer: Nathaniel G. Herreshoff

Sailboat Calculations

S.A. / Displ.: 19.34
Bal. / Displ.: 58.80
Disp: / Len: 285.71
Comfort Ratio: 13.66
Capsize Screening Formula: 2.17
Hull Speed: 4.74 kn
Pounds/Inch Immersion: 260.39 pounds/inch

calculation mobile

2 nd ad half width

3rd ad full width


Gaff rig until 1936. From 1937 onwards, one could choose either a gaff or Marconi rig.
The original boats were built by Herreshoff Manufacturing beginning in 1914 (357).
From 1943 to 1948, more were built by Cape Cod Shipbuilding (34 + 200, later in fiberglass), as well as the Quincy Adams Yacht Yard (51).
Cape Cod Shipbuilding came out with the BULLSEYE, built of fiberglass, with a similar hull but a different rig.
The DOUGH DISH, (one of the many nicknames previously associated with the class)is a faithful rendition of the 12 1/2, first built in 1972 of fiberglass by Doughdish Inc., of which 575 were built. They have been recognized and approved by the class to race on equal footing with the remaining, original wood boats.
Class rules permit a spinnaker of 140 sq. ft.