When we were last in Papeete, the beach was off limits due to sewage dumping. Many Caribbean islands only have cess pits. They get pumped out and then sewage is deposited in caves on the windward side. They depend on tides and wave action to clean out the caves. Before tourism, these places would designate an area as “s#!+ beach” and everyone would use it as a communal toilet. The larger foreign-owned resorts sometimes have their own water treatment facilities, but not all of them.
Many of these same islands, especially the arid ones, irrigate the resort plantings with so-called gray water, which stinks and is really black water. It gets tracked into the already over-chlorinated pools and every week, kids and older folks are made ill.
We have a sailboat which sits in a marina. It is totally legal, acceptable, and every boat does it. Gray water goes straight into the ocean. Showers. dish water. etc.