The ultimate diving site is Sabah, which is a must visit for every diver is Sipadan. It's paradise down below. Just in one dive you can see green and hawksbill turtles, schools of barracuda, schools of big-eye trevally, bumphead parrotfish, manta rays, eagle rays, scalloped hammerhead sharks and whale sharks. There is a quota of 120 divers per day, which is still too many people if you ask me. It's best to come during low season when you can enjoy the underwater view more.