FED, not heard about that. I know they dropped Blue Danube shapes off Jurby Head. Fishermen complain their nets get caught in them.
In the 60s and before there was The Wash Jettison Area. This was actually further north than The Wash.
For interest, ballistic computation of forward throw was done by the Calc 3 into which was fed the ballistic properties of the bomb to be dropped. We used a 'ballistic cassette' which contained a 35mm film and was like a punched paper tape through which a light was shone.
Until the late 60, as all bombs were dropped from high level, we used the Ideal Bomb which did not suffer any drag. This film was Bomb Type Zero. Using the Ideal Bomb for forward throw (the crew would not have had the real ballistic data) would result in a longer forward throw. A real bomb dropped using Ideal Bomb forward throw might land over a mile short of the target.