Jon May was born in 1947 in the old Steelhouse Lane gun-making quarter of Birmingham. His father was Cornish and his mother Welsh. When he was four years old, the family moved back to Cornwall to run a small hotel. He was educated at Truro School, a small Public School in Cornwall. From there he went up to the University of Hull to read Life Sciences and graduated in 1970.

After that he had a series of jobs ranging from Fisheries Biologist for the White Fish Authority to running a production line for Ross Group before finally switching to teaching life science. After some time he had a chance meeting with a deep sea diver who introduced him to the North Sea industry. He trained first as Life Support Supervisor than as Offshore Diving Medic at the Underwater Centre in Fort William and then at the Hull Royal Infirmary and Normed, the sector medical centre in Yarmouth.

After that, he joined Comex Houlder Diving at a time when the rate of attrition among divers ranged from the bad to catastrophic. In the following years, he worked for most of the major contractors in the North Sea and then, as work dried up in the oil slump of the eighties, he worked distant waters from Africa to India and the South China Sea Fields.

Five years ago he moved back to Cornwall with his wife of thirty five years. They live in Falmouth within sight of the sea and the harbour.