An orange survival dinghy, with Mr Ogston inside, was found by an RAF helicopter near the Piper and Brae oil fields. The body of his step-mother, Elizabeth Ogston, was later found in the sea five miles away. A search was continuing until nightfall for his father, Ian.
On Tuesday morning, Mrs Ogston made a routine call to coastguards reporting her position and informing them she was on passage from Stavanger to the Scottish port of Fraserburgh.
At 09.28 GMT a rig 100 miles north east of Aberdeen heard a woman's voice repeating the word Mayday, then there was total radio silence.
The family, from Livingston, near Edinburgh, was returning to Scotland after their 32ft yacht, Drummer of Hornet, took part in last month's Banff-Stavanger, Norway, yacht race. Rescuers believe the yacht was either hit by a large wave or struck an obstacle.Reuse content