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Sailboat Specifications

Aloa 21

Masthead Sloop · Fin Keel

Designed by J.m. L´hermenier · Built by Aloa Marine (Fra)/Seb Marine · First built 1969

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LOA 20.67 ft  ·  Beam 8.04 ft  ·  Displacement 1,323.00 lb  ·  Sail Area 187.00 ft²  ·  Masthead Sloop  ·  Fin Keel
About the Aloa 21 Sailboat

Designed by French naval architect J.M. L'Hermenier and built by Aloa Marine from 1969 to 1979, this compact sloop represents classic European small-boat design philosophy of the era. With 400 hulls produced during its decade-long production run, the Aloa 21 earned a solid reputation among sailors seeking an affordable entry into cruising. The boat's proportions reveal a thoughtful balance between performance and stability. Her masthead sloop rig carries 187 square feet of sail area on a hull with nearly 50% ballast ratio, creating a stiff, seaworthy platform despite her modest 20.67-foot length. The fin keel configuration provides good windward ability while maintaining reasonable draft for exploring shallow waters. Built with fiberglass construction typical of the period, the Aloa 21 suits coastal cruising and daysailing particularly well. Her comfort ratio of 6.8 indicates moderate motion in a seaway, while the capsize screening value of 2.93 suggests reasonable stability for protected offshore passages in experienced hands. The hull's design speed of 5.67 knots reflects honest small-boat performance expectations. This French design appeals to sailors wanting traditional cruising character in a trailerable package, offering genuine sailing capability rather than compromising for pure comfort or speed.

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Dimensions & Specifications
LOA (Length Overall) 20.67 ft / 6.30 m
LWL (Waterline Length) 17.88 ft / 5.45 m
Beam 8.04 ft / 2.45 m
Max Draft 3.28 ft / 1.00 m
Displacement 1,323.00 lb / 600 kg
Ballast 661.00 lb / 300 kg
Sail Area (Reported) 187.00 ft² / 17.37 m²
Design & Construction
Hull Type Fin Keel
Rigging Type Masthead Sloop
Construction FG
Designer J.M. L´Hermenier
Builder Aloa Marine (FRA)/SEB Marine
First Built 1969
Last Built 1979
Number Built 400
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Frequently Asked Questions

What is the Aloa 21's sail area to displacement ratio?

The Aloa 21 has a Sail Area to Displacement ratio (SA/D) of 24.88. Values between 14–18 are typical cruising sailboats; 18–22 is cruiser/racer; over 22 is performance racing.

What is the Aloa 21's comfort ratio?

The Aloa 21 has a Ted Brewer Comfort Ratio of 6.8. A ratio over 30 indicates good offshore comfort; over 40 is very comfortable offshore.

Is the Aloa 21 safe for offshore sailing?

The Aloa 21 has a Capsize Screening Formula value of 2.93. Values under 2.0 are considered acceptable for offshore sailing; under 1.8 is ideal.

What is the hull speed of the Aloa 21?

The theoretical hull speed of the Aloa 21 is 5.67 kn knots, calculated from its waterline length.

How much does a Aloa 21 weigh?

The Aloa 21 has a displacement of 1,323.00 lb and a length overall (LOA) of 20.67 ft.

Who designed the Aloa 21?

The Aloa 21 was designed by J.m. L´hermenier, first built in 1969.