Well, I dunno there.
I think the rich perps were people people with lots to lose, not at all used to letting their hair down at all, and this experience of going to an ISLAND was in some sense intoxicating for many of them.
I've seen it a million times in tourists who get on a boat for the first time, or even the millionth time after a long time of not being on a boat:
A LOT of them start waving, waving, waving at strangers, then birds, ducks --the works. They get changed, for a time, do things they ordinarily woudn't do.
And I think LSJ had a similar effect; Esptein had to convince them they'd been transported to a place where, magically, the normal rules did NOT apply and that therefore, they were FREE. A kind of Xanadu, if you will.
And another part of it was them all seeing him DIG IN without any reservation at all; to demonstrate the water was fine, that there wasn't any danger, and that they, too, could jump in and quack around, just like him. And forget, for a short time, all the crushing responsibility from which they come, on the mainland.
So I 100% disbelieve mini-subs descending from inner hull wet bays, etc. But the idea that suck, crazy stuff was going on ou there?
Oh, yes, I believe THAT completely.
The kindest face you can put on the thing still demands that those involved die of old age in prisons.