The diving season for Costa Rica is year round, the conditions in some areas do vary though depending on the time of year. Liveaboard diving in Caño marine reserve is during the dry season from January until June. Cocos island on the other hand is fantastic all year, although most liveaboard diving is done in the wet season around June to December. This is due to plankton blooms in the wet period, which attract more hammerheads, mantas and whale sharks.