Clive Godden, 49, was with a friend on Loch Fionn in Wester Ross when the boat overturned on Friday afternoon.

His companion managed to swim ashore but Mr Godden, who comes from Buckinghamshire, has not been seen since.

A search began after Mr Godden was reported missing, and after being halted overnight it began again on Saturday morning.

Coastguards said search efforts had failed to find any trace of the man on Friday.

The weather and visibility in the area was good at the time

Coastguard spokesman

A small plastic boat occupied by the two men sank shortly before 1800 BST on Friday while they were fishing on Loch Fionn, near Loch Ewe.

A passer-by contacted police in Dingwall to raise the alarm after one of the men swam to safety.

The Stornoway Coastguard helicopter, Loch Ewe and Ullapool Coastguard Rescue Teams and Northern Constabulary were involved in a search of the remote area.

The friend of the missing man also helped the teams searching the shoreline.

Scaled down

A coastguard spokeswoman said: "The weather and visibility in the area was good at the time."

A spokesperson for Northern Constabulary said the missing man was part of a three-strong group from England who were staying at nearby Gruinard.

"Unfortunately with the passage of time the likelihood of finding this man alive is diminishing," added the spokesperson.