Jay Z's Motorboatin' with Beyonce

Jay Z and Beyonce are running the best damn summer camp EVER for Blue Ivy ... latest stop -- Monaco!!!

The Carters hit the Mediterranean with their daughter and some friends over the weekend. Check out the pics ... Bey looked flawless while Hova rocked a Gilligan bucket hat.

This trip came just a few days after Blue was sleeping in Mom and Dad's $19,000/night suite in Paris.