The diver, named as Maurice Bell, 67, from Rothwell in Northamptonshire, was in a diving group of ten from Corby and District Sub-Aqua Club.
His problems began under water while on a dive yesterday, 18 April off Calve Island’s northern coast. Other divers were able to get him back to the dive boat, Gaelic Rose.
He was taken aboard and given treatment as an emergency call was put out. Tobermory Lifeboat was launched and a helicopter scrambled from HMS Gannet in Prestwick.
Bell was taken aboard the lifeboat, accompanied by one of the divers who was a nurse. He died before the lifeboat reached Tobermory harbour, where an ambulance and doctor awaited.
The skipper of the Gaelic Rose, Bob Jones, said that the diving group had been regulars on his boat. He described them as experienced, adding that they always dived in buddy pairs.
The police have confirmed that a report will be submitted to the procurator fiscal, but that there are no suspicious circumstances surrounding the incident.