Three-time Olympic champion
has won a record sixth Finn world title at Falmouth Bay in Cornwall.
Ainslie had a 20-point lead going into Friday's medal race, meaning he only had to start to ensure taking gold.
But low winds forced an abandonment, giving the 35-year-old victory and team-mate Ed Wright a silver medal.
"I am really happy with how things have gone, it has been a great competition and now I am looking forward to the Olympics," said Ainslie.
"It is great. I am very happy. It was a shame today that there wasn't enough wind to race because we have had a fantastic week of racing down in Falmouth."
Ainslie is the third Briton in as many years to win the world title, after Wright in 2010 and Giles Scott last year, and his sixth title is three more than anyone else has won in history.
He will compete in one more event, the Skandia Sail for Gold, before the Olympics and was in fine form all week as he won seven of the nine races.
"Any world championship, no matter what year it is, is a big deal," Ainslie said.
"But the Olympics is what we're all working towards so for me there is still plenty to work on and lots of improvements to make.
"I certainly won't be relaxing at all in the next couple of months in the build up to the Olympics."