The victim was taken to Daniel Freeman Marina Hospital where he was pronounced dead.
Friends called 911 around 11 a.m. on Saturday after the man failed to emerge from the water just north of the Venice breakwater off Horizon Avenue.
So far, there is no word on the victim's identity but he is said to be around 40 years old.
A 31-year-old man drowned early July 5 after jumping off the Venice Pier. The body of Brian Patrick Dunn, a West Hollywood resident originally from the Philadelphia area, was recovered July 11 a few miles to the north in Santa Monica.
CNS contributed to this report.