A woman who died after being pulled from the sea off the coast of Northumberland had been with a party of divers.
The woman, said to have been aged around 50, disappeared after surfacing just after 11am on Sunday while diving near the Farne Islands.
A search and rescue operation was mounted by the coastguard including helicopters and lifeboats - with sirens prompting the woman's partner to ask what was happening as he walked dogs near the harbour, a local RNLI manager said.
Police were called at 1.50pm and the woman, with a group of divers from Ormskirk, Lancashire, was later found and pulled from the water before receiving aid, but died a short time later.
Ian Clayton, lifeboat operations manager at Seahouses RNLI, said he understood the woman was "approximately 50" and added that he believed she had been a swimming instructor.
He said it was "very harrowing" because the woman's partner was near the harbour when the rescue operation was launched.
Mr Clayton told the Press Association: "He heard the sirens go off at the lifeboat station, and he came down to see what was happening.
"And he was then told that obviously the lifeboat's launching to go to the assistance of a boat that's reported a diver missing.
"And that was his partner, and he didn't know obviously at that immediate time that it was definitely his partner."
Mr Clayton said it had been the first weekend of the diving season, and added: "There can be no criticism directed to the boat operator or boat skipper. What happened was obviously some sort of accident that's happened whilst the lady's been in the water.
"We are unsure how this tragedy occurred, but our thoughts are very much with the deceased lady's partner, friends and dive colleagues.
"She had come from a party of divers from Ormskirk. Northumbria Police are now conducting inquiries, which will be referred to the coroner. This was a very harrowing incident for all concerned."
A Northumbria Police spokesman said: "The coastguard launched a search of the area and at 2.30pm the diver was located. She received medical attention at the scene but unfortunately passed away a short time later."