The Looc Fish Sanctuary is a protected marine area in the middle of the bay at Looc town, Tablas, Romblon. The sanctuary is home to many species of fish and a nice (although not spectacular) coral reef. The local government there seems to understand the importance of tourism, and has gone to great lengths to preserve the reef and fish life, even posting guards out on the bay overnight to prevent illegal fishing in the sanctuary.
The pier is only a short (200m) walk from the town square. There is an office at the pier where you pay the P100 per head fare for the boat ride to the sanctuary (no booking is necessary). You can also rent a mask and snorkel here for P50. It’s then a short (5 min) boat ride to the permanent floating shelter at the sanctuary.