Flight time would be about 1 hour, 80-120 miles.

Some candidates I've been looking at a
Max Holste "Broussard"
Grumman G-44 Widgeon
DHC Beaver

The water landings will be in a protected cove or leeward side of an
island not in the surf.

A surf company has taken this on a much larger scale with an Albatross.

http://www.billabongclipper.com/clipper/main_page.html