Bourgnon disappeared at sea during a dive on 24 June.
"He will stay here, I leave him to you. Take care of him," Caroline Bourgnon said.
She was surrounded by over a dozen sailboats around the Matavai bay, where British explorer James Cook anchored his vessel a few centuries before.
The ceremony took place two days after one in Raietea, a key navigation spot in the archipelago of the Leeward Islands, where Bourgnon had spent five years with his family before moving to Tahiti in 2014.
Bourgnon won two titles at the four-yearly transatlantic yacht race, the Route du Rhum, in 1994 and in 1998.
Widely respected in the sailing community, Bourgnon is above all remembered for his "humility" and "generosity".
He sponsored Saga, a charity for handicapped and underprivileged children who are given the opportunity to sail during the summer.
"Laurent is in his element now. For the best or the worst, this is where he was meant to be," Tahitian Sailing Federation president Thierry Hars told the AFP news agency. "We will keep him, we are going to take care of him. Besides, he is wherever the sea is."
Bourgnon leaves behind his wife Caroline Bourgnon and his four children in France.