Various attempts were made to enter these underwater cave systems using shore-based pumped-air diving suits, without much success.
[1][2] Sheppard constructed his own dry suit, incorporating an oxygen rebreathing system, and used this to make the first successful cave dive in Swildon's Hole on 4 October 1936.
This amazing contraption was constructed with recycled household items, including a bicycle pump and tobacco tin.
It is a kind of homemade snorkel but designed to be attached to a pump to supply the air for underwater cave diving.
[4][5] During his later life, Jack Sheppard was made Honorary President of the Cave Diving Group.