I honestly dont understand this
I have been "sitting" on my thin 118 board and others just as small that "sink", and on my medium as well as huge volume big board, NO issues whatsoever and huge benefits in terms of launching (and being much safer) in light wind.
If you can not relaunch, you can redirect the mast so you get ashore where you want to - and you have a good overview no matter how small the board is, as you ARE up a bit higher even on the tinyest small board.
Also, when water is cold, you can keep your head and hands warmer, being higher - if you have to drift all the way to shore.
Find it really odd that some of you can not sit on your board, no matter what size it is ???
When you sit on the board, you can either stall the rear end down, or turn the board to the side and maybe even tilt it a bit - so in both cases it acts like a really good anchor, to give you even better relaunch options.
Besides lots of time, because it is so comfortable - I would never want to be IN the water for long, at least not in deep water if only boardshorts