The whole point of Coron is day-tripping by boat — Coron Island, the wrecks, the outer Calamian beaches all qualify. Beyond that:
Culion — the former leper colony — is an hour by ferry south and worth a half-day. The Spanish-era fort, the Culion Museum (in the old hospital, with displays on the leprosy programme), and the painted Sanctuario de la Inmaculada Concepción on its hill above the harbour together make for one of the strangest and most affecting visits in the Philippines.
Concepcion Falls, on the Busuanga mainland about an hour from Coron town, is a freshwater swimming hole — a good change after days of seawater.
Black Island, with its haunted cave and small white beach, is a long but spectacular boat trip from northern Busuanga, often combined with Calauit Safari Park into a full-day northern circuit.