Curved, or wrestling
Hana is a bay and uma is either curved or the hand-wrestling contest. Both readings are given: the bay is a near-perfect curve, and the area is also recorded as a place where chiefs held uma contests.
The bay is a tuff cone breached by the sea. The reef inside it is now a protected nature preserve — entry is capped, reservations are required, and visitors watch a briefing before going in, after decades of damage from unmanaged snorkelling.