I went on a joyride in Hawai in a C206 on floats. The operator told me he had 26,000 hours in seaplanes, and was looking for another thousand to beat the record.
He also stated he had spent 9 years trying to get approval from various agencies before he was cleared to start flying in Hawai.
I remember watching the flying boats taking off from mechanics bay in Auckland when I was a kid, and later the military Sunderlands in Suva. It was interesting doing engine runups with no brakes. And mooring them after flight involved shutting down all four engines and drifting, drifting, drifting until the engineer could grab the mooring buoy with a boathook.
Airmanship was needed but so was seamanship.