To answer some questions, it seems easier said than done to get on the boat from the beach BUT...
If there is wave or wind action it will stir up the bottom then you cannot see where you are stepping. This happens more often than you think in 2-3 feet of water right at the waters edge. The shore where I do this is a mix of sand and ironshore. If you have been to Bonaire, its like an easy Bonaire entry. I am not afraid to wade in, nor am I alarmist, but if the bottom is cloudy this would be dangerous and you better be wearing hard bottom boots.
Speaking only for 3P, those guys are pros at this.
We would wade in Day 1. Drop off would be a quick action dock drop off where you get out before anyone realizes then hustle off. Day 2 would be similar. By Day 3 they are picking you up on the dock because they know exactly what you look like and tell you ahead of time to move fast. You just jump in the boats before anyone knows what the hell is going on acting like a confused tourist and the moment you are on they fly off. On multiple occasions we have been dropped off into the shop boats (!!!) and crossed them to get to the dock with the boat hands for the shop actually helping us. I get the impression 3P guys enjoy sticking it to the man almost like its little challenge to outwit the pier police and drop us off on the dock.
ymmv....