Central Island Plateau (EL 3 to 4 at surface, 2 to 3 in shallows)

Plateau/valley ^ surrounded by steep rock #. From outside looks like a raised rocky island with cliffs. At the top it is wind-scoured stone with wet scrub jungle and ancient ruins/landmark.

This is the exploration hook or lure. Land-based predators, territorial creatures, and ruins hinting at older settlements and civilizations. May be more dangerous here than the water around the shoals.