Built of 5/8in pitch pine planking on 1in x 5/8in English oak or American elm timbers, spaced at 6in centers. They have a bolt-on keel made up of 4in thick pieces of white pine, bolted together bread-and-butter style, and a 1.25-ton ballast keel.

Boats with bolt-on keels were quicker to build than ones whose planking fairs down into the keel. The design also has relatively big 3in x 3in oak floors.

All ECOD’s are three quarter decked, although Widgeon (Design No. 2), has been converted to a cruiser and now has a small cabin. Originally they would have had teak or mahogany coamings lining the cockpit and the deck would have been 6 x 5/8in white pine covered with Linoleum.