I did check to see where the closest Coast Guard stations are located in Hawii.
One is at Barbers Point near Kapolei WSW of Honolulu. It looks like they would be the ones to dispatch air assets for water rescues.
The other is a Coast Guard auxiliary station on the west side of Maui and one on Kauai.
http://en.wikipedia.org/wiki/List_of_United_States_Coast_Guard_stations
Hawaii is in the 14th district.
Maui is very close. Kauai is about 40 minutes away by air.