At Dorney Lake, the women's rowing eight - which includes Katie Greves from Henley - finished third in their heat. It means they'll have to qualify for the final with a good performance on Tuesday.
Iain Percy from Winchester and Sherborne's Andrew Simpson steadied the ship after coming 11th in their first race of the Men's Star class. The defending Olympic champions came second in their second race, in a photo finish, and lie in third place overall - with another nine races to go.
Ben Ainslie, off the shoreline at Weymouth, competes on the second day of the London 2012 Olympics
Team GB said: "Ben Ainslie got his bid for a fourth consecutive Olympic gold medal underway on the opening day of the Olympic regatta at Weymouth and Portland on Sunday. Ainslie, 35, recorded two second places in both of his Finn class races today.
A Gold medal at London2012 will see Ainslie tie with Danish sailor Paul Elvstrom’s Olympic record of four golds, which has stood since the 1960 Olympics in Rome. “Compared with my last Olympics it's nice to get two solid starts,” said Ainslie after his second race.
Great Britain's Ben Ainslie competes in the Men's Finn sailing on the second day of the London 2012 Olympics. Second is an excellent finish for Ben, who is normally a slow starter in this type of competition.
Great Britain's Ben Ainslie has finished a creditable second in his opening race in the Finn class. There is a league table involving 10 races. Ben, from Lymington in Hampshire, is usually a slow starter - he's thrilled with his early success.
Gemma Spofforth, the West Sussex swimmer, is into the semi-finals of the 100 metres backstroke at the Aquatics Centre. The event, this evening, will also involve her GB team-mate Georgia Davies.
Great Britain's Mark Hunter (right) and Zac Purchase react after a lightweight men's rowing double sculls heat in Eton Dorney on Sunday. They are into the semis after winning the men's lightweight double skulls heats.