The Maldives are a rather idyllic float flying environment, so variations on the norms seem to work there. As for footwear, it's 99% sure that the next thing you're going to step on will either be beautiful sand or a smooth dock, and stepping into warm water at a island is likely. When I flew there for a few flights (and wore shoes), I was overdressed! The operators there have things down to a fine art, and are crewed very well. That is one of the few exceptions to the rule - wear personal protective equipment, and keep it on!
I do have a pilot friend who sank a Caravan there. He said he just climbed on top, and waited to be rescued!