Philippine Siren

Routes: Runs Tubbataha Reefs during the short spring season, then Visayas and Coron itineraries taking in thresher shark territory, wartime wrecks and muck sites through the rest of the year.

Season: Tubbataha is only diveable mid-March to mid-June; other Philippine routes fill the remainder of the year.

Character: Philippine variety from remote atoll walls to critters

For photographers: Camera stations with charging and air guns, standard across the Siren yachts.

Prices: Roughly $350-500 per night with Tubbataha commanding a premium plus park fees. Fleet rosters change; make sure the vessel and dates you want are actually operating before booking.

Departures: Puerto Princesa for Tubbataha; Cebu and Coron serve the other loops.