Big Fishes Deep Drift Wall
Usually you will enter the channel at the end of a drift dive coming from Small Fish Country. You can rest a while at the lower rim of the channels entrance at "Big Fish Country".
Dive only at beginning high tide when the current is flowing into the lagoon. Sometimes 6+ knots current! Try reef hooks on a long rope but watch out that the current doesn't pull the mask from your face. :-) You'll see eagle rays, barracudas, groupers and sometimes whalesharks!
When you're out of air which can be very soon due to the current just let go and swim to the left side of the channel. The current will pull you into the channel which is about 20m deep and approx 100m wide. The ground is polished rock without coral. After 20 meters you'll see the entrance of a cave on the channels floor at the left side. There live giant groupers. It would be nice to explore that cave between the tides but no one has ever done that yet. When floating into the lagoon you can either stay shallow and look at the corals while drifting by or you can go in the center of the channel and drift into the deeper parts. But you'll need a lot of air left to do that. Hammerheads have been seen there and also there is a deep basin going down to more than 35m where a big school of eagle rays dwells. This extended drift dive requires very low air consumption, believe me. ;-)