John G. Alden “O Class”

Alden “O Class” Specifications:

LOA: 18′ 01″ / 5.51m – LOD: – LWL: 15′ 05″ / 4.70m – Beam: 06′ 08″ / 2.03m – Draft: 01′ 01″ (Board up) / 0.33m – Ballast: 550 lbs – Displacement: – Sail Area: 192 sq ft – Yard Number: 188 – Hull material: Wood construction – Rig: Fractional Sloop Rig – Designer: John G. Alden – Built by: – First Year Designed: 1924 – Number Built: 600 – Restored By: – Current Name: – Original Owner: – Contract Price: $650.00 – Current Owner: – Sail Number:

Known Racing History: ?

Known Restoration History:


In terms of numbers, the O class is the most popular, designed for a group of Marblehead, Massachusetts, yachtsmen, as trainers for teenage sailors. Two variations were built, one for moderate weather, and the other for heavier winds. For safety and comfort, the boat was given plenty of freeboard, a deep cockpit with coamings, and a watertight bulkhead forward to prevent the 550 lbs of ballast from sinking her, in the event of capsize.




Written by

Please feel free to comment about ClassicSailboats.Org posts, your knowledge will make our website a better experience for all users.


  1. Gerardo

    Dear sirs. I just recieve the photo colección SaIling 1917 -1934

    I want to confirm if the 4 boats with an “O” on the sail correspond to the Alden ” O boats”.
    Photo reference is :
    File name: 08_06_012708

    Title: Sailing

    Creator/Contributor: Jones, Leslie, 1886-1967 (photographer)

    Date created: 1917 – 1934 (approximate)

    Physical description: 1 negative : glass, black & white ; 4 x 5 in.

    Genre: Glass negatives

    Subjects: Sailboats; Sailing

    Notes: Title from information provided by Leslie Jones or the Boston Public Library on the negative or negative sleeve.; Date supplied by cataloger.

    Collection: Leslie Jones Collection

    Location: Boston Public Library, Print Department

    Rights: Copyright © Leslie Jones.

    Preferred credit: Courtesy of the Boston Public Library, Leslie Jones Collection.

    I’m colecting data and photos of 12 O boats Alden design built in Quilmes , Argentina in 1931.

    Regards Gerardo

    • admin

      Designed in 1921 for Marblehead MA sailing conditions.

      Two design references in the Alden index:
      169 – LOA: 18’2″ x WL: 15’6″ x Beam: 6’2″ x Draft: 1’0″ x 200 sq ft x 450 lbs (inside ballast)
      188 – LOA: 18’1″ X WL: 15’5″ X Beam: 6’8″ x Draft: 1’1″ X 550 lbs x 192 sq ft (inside ballast)

      Some clubs choose to switch sail plans to suite their requirements, adding to some confusion. The picture you are referring to, shows all boats sailing together with the “O” lower on the sail, with the sail number higher.

      In reference to the collection there is another photo that shows all boats racing together with O’s higher and lower, and also sail numbers within the O’s, so in our best opinion the picture shows the John Alden “O” boat, and placement of the O’s was the sailmaker/owners choice, and possibly by logo upgrades as the years passed.

Leave a comment

Time limit is exhausted. Please reload CAPTCHA.