Double Boiler is a steel-hulled steamship wreck off Goa that is best treated as a guided boat dive. The wreck gives you a clear traverse from the bow through the engine section to the stern, with machinery and ship structure as the main draw. Expect a seasonal wreck rather than a calm reef, with limited visibility and enough current to reward steady buoyancy and good local briefings. It suits experienced wreck divers who want structure, history and a bit of search-and-reward.