From the history of the British Moth ;
The British Moth's ancestor is the American Moth, which was popular across America in the 1930's, almost 1500 moths were registered with the American Moth Boat Association. Based on this, Sydney Cheverton designed a boat more suited to British waters.
The length of 11 ft. was retained, with the scow bow and hard chine construction. The mast was increased to 20 ft. carrying a sail of much higher aspect ratio but smaller overall area (75 sq ft. to 63.5). The small cockpit with wide side decks was retained to permit "dry" capsizing.
The British Moth, as the name indicates, is solely a British class. It remains the most popular Circle M Moth with consistent 30's attendance at their national championships.
Here is a Youtube on the British Moth which popped up recently. You have to overlook the sound track which seems to have been stolen from some kiddies TV show, but the sailing looks good.