Hull construction:
The hull was laminated or moulded according to the designer’s plan for glass mats. The underwater was laminated with clear gelcoat which allowed perfect control of the positioning of glass matts later, which themselves had been marked at their sides. Moulding was done to extremely high standards which was confirmed by boat builders at the time. The underwater area moulding usually was done so well that one could look straight through the unstained hull.

The hull is stiffened with 7 longitudinal foam stringers on each side. Major chainplates are fixed to the hull through molded-in plywood boxes which provide excellent stiffness and distribute forces very evenly to the hull. A similar construction principle has been chosen for the design of the bow.

Watch for the stringers in this O-38 built in the Svineviken yard in early 1969: Actually it is SERIPHOS (US 2765) under construction. 

Photograph: courtesy of Kevin Swope

Manufacturing of the hulls was given to the Tyler Boat Company in Tonbridge/Kent UK, then the world’s leading GRP manufacturing company. There is a reference on their