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Sailboat Specifications

Cape Bay 31

Masthead Sloop · Long Keel W/Trans. Hung Rudder

Designed by Bruce King · First built 1977

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LOA 30.92 ft  ·  Beam 10.42 ft  ·  Displacement 11,400.00 lb  ·  Masthead Sloop  ·  Long Keel W/Trans. Hung Rudder
About the Cape Bay 31 Sailboat

Designed by renowned naval architect Bruce King and built from 1977 to 1982, this substantial 31-footer represents classic American cruising design from sailing's golden era. With its traditional long keel configuration and transom-hung rudder, the Cape Bay 31 offers the directional stability and sea-kindly motion that made this hull form a favorite among serious cruising sailors. The boat's impressive 11,400-pound displacement and generous 4,500-pound ballast create a stiff, confidence-inspiring platform well-suited for coastal and offshore passages. Its excellent comfort ratio of 29.85 indicates outstanding motion characteristics in a seaway, while the conservative capsize screening value of 1.86 reflects inherent safety for extended cruising. The masthead sloop rig provides versatile sail handling options and reliable performance across varied conditions. Bruce King's design philosophy emphasized seaworthiness over speed, and the Cape Bay 31 delivers accordingly with solid fiberglass construction and thoughtful proportions. The moderate beam and deep draft contribute to impressive tracking ability and windward performance, though docking flexibility may be limited in shallow venues. This design appeals to sailors prioritizing comfort, stability, and blue-water capability over racing performance, making it an enduring choice for serious coastal and passage-making adventures.

Dimensions & Specifications
LOA (Length Overall) 30.92 ft / 9.42 m
LWL (Waterline Length) 23.92 ft / 7.29 m
Beam 10.42 ft / 3.18 m
Max Draft 4.92 ft / 1.50 m
Displacement 11,400.00 lb / 5,171 kg
Ballast 4,500.00 lb / 2,041 kg
Headroom 6.08 ft / 1.85 m
Design & Construction
Hull Type Long keel w/trans. hung rudder
Rigging Type Masthead Sloop
Construction FG
Designer Bruce King
First Built 1977
Last Built 1982
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Engine & Accommodations
Engine Make Universal
Engine Type Diesel
Horsepower 16
Fuel Capacity 35 gals / 132 L
Water Capacity 45 gals / 170 L
Frequently Asked Questions

What is the Cape Bay 31's comfort ratio?

The Cape Bay 31 has a Ted Brewer Comfort Ratio of 29.85. A ratio over 30 indicates good offshore comfort; over 40 is very comfortable offshore.

Is the Cape Bay 31 safe for offshore sailing?

The Cape Bay 31 has a Capsize Screening Formula value of 1.86. Values under 2.0 are considered acceptable for offshore sailing; under 1.8 is ideal.

What is the hull speed of the Cape Bay 31?

The theoretical hull speed of the Cape Bay 31 is 6.55 kn knots, calculated from its waterline length.

How much does a Cape Bay 31 weigh?

The Cape Bay 31 has a displacement of 11,400.00 lb and a length overall (LOA) of 30.92 ft.

Who designed the Cape Bay 31?

The Cape Bay 31 was designed by Bruce King, first built in 1977.