This photo is from the 1961 London Boat Show, held at Earls Court.
The yacht on the left is a Brabant class sloop and the smaller boat to the rear is a Crystal class, both designed by Alan Buchanan. I’m not sure what class of boat the upturned hull is from. Fortunately one doesn’t see boats from this angle too often. It might be a Bonito class GRP hull from Seamaster. More research needed.
Photo by Fox Photos Ltd.