Leonardo DiCaprio Having Fun In The Sun With Family On Amalfi Coast

Leonardo DiCaprio is cooling off after spending time with a bunch of hot models ... having a blast with some of his family as his vacation continues on the Amalfi Coast.

The actor took a big leap into the water Sunday off a beautiful yacht ... soaking in some rays with his niece Normandie -- as well as his pops George and stepmother Peggy.

The gang's sleeping on the boat -- but took some time off for a sweet excursion, checking out the Blue Grotto sea caves in Capri.

As we reported, Leo went from the Cannes Film Festival to relaxation mode at the end of last month, lounging on the big boat with some of his buddies, including Tobey Maguire.

Of course, we've seen Leo with a couple of babes during his time abroad -- 22-year-old model Meghan Roche spent a night on the yacht with him, although there wasn't a lot of PDA going on ... at least, as far as we could see.

He also recently grabbed dinner with Gigi Hadid, his dad and stepmom, and a bunch of other folks at a big dinner party in London ... and followed it up the next night by arriving at the same hotel in separate cars -- with Gigi ridin' with George and Peggy!