Blue Lagoon is a sheltered Drvenik Veli bay that works well for beginner dives, snorkeling and easy half-day water time. The underwater shape is simple: shallow sandy bottom with Posidonia patches and low rocky pockets, so the interest comes from relaxed exploration rather than big relief or depth. It is best approached by boat, and the main planning issue is heavy summer boat traffic rather than strong current; small fish, octopus and eels are the usual wildlife payoff.