divers in blue hole in palau

adventure animals beautiful behavior biodiversity blue calm camouflaged cave cavern change climate conservation coral corals critter diving dropoff ecosystem environment fish geology habitat half healthy hole idyllic island landscape muck national natural nature new niche ocean outdoors over pacific palau park peaceful reef reefbuilding relaxing remote research sand scenery scenic school science scuba sea seafloor seas seascape shallow sink sinkhole sky snorkeling split tourism tourists travel travelers triangle tropical tropics under underwater vacation warm water wild wilderness wildlife