J-Caves is the closest thing northern Ha'apai has to an underwater maze. The dive starts on the sheltered inside of the reef system and works literally through it — a sequence of swim-throughs, winding tunnels and massive overhangs threading between huge coral bommies until you pop out on the outer reef face, where the wall falls away into darker blue water before the route winds back up into fish-filled shallows.
It's an atmospheric dive rather than a demanding one: maximum depth is about 28 m out on the face, most of the route sits much shallower, and the tunnels are wide enough that any comfortable certified diver can enjoy them.
Keep an eye on the blue for eagle rays and passing whitetip reef sharks, but the real prizes here are small. Whip-coral shrimps and orangutan crabs hiding in bubble coral head a long list of critters that make J-Caves a favourite with macro photographers, and the shallows at the end of the dive are thick with reef fish over healthy hard coral.
