Cocos Island is hands down the best diving in Costa Rica, and one of the best locations in the world. For diving fanatics, there is no comparing Coco Island to anything else. It is one of the largest uninhabited islands in the world, but its waters are teeming with wildlife. Huge schools of hammerhead sharks and white-tipped reef sharks, whales, manta rays, dolphins and fish species too many to list, put Coco Island as a top ranked diving location in the world. Seven to ten day chartered boat tours are available.