German Channel
This site is famous for manta sightings.
At the cleaning station, you can observe not only mantas but also sharks being cleaned.
Even if mantas do not appear, you can still see large schools of bigeye trevally, Kumasasahanamuro, and blackfin barracuda. In the sandy areas, countless garden eels can be seen poking their heads out.

The Palau Underwater Point Map illustrated on this website is available as a set at Splash Dive Center.