Just a curious question. On a bodyboard or a skimboard you can throw some seriously thick lines of water off a cutback. A shortboard...doesn't allow you to do this. Maybe off a top turn where you throw the water high in the air, but you don't get that same thick sideways spray. I think this is because of the fins on the tail stops the water from going across the bottom of the board.
A sup however, might be different. I think this is because an 8ft plus sup on a wave has at least a bodyboard worth of surface area in the water that does not have fins attached to it, and if you can tilt the board so the the fins are buried in the water, and the bodyboard size surface area is slicing the water unabated, you could throw some thick, thick lines.
To do tthis guess you would have to get an 8ft 30 wide board or bigger and stomp the tail on a cutback, to the point where the board is at at least a 30 degree angle to wave. That would place the fins underwater.
Is this possible? Has it been tried before much?
You can throw huge spray on a shortboard (look at any good surfer), but it is technically harder because you must use your board both to deviate water into the air, and keep your balance and momentum. You have to compromise.
In my opinion, it is easier to do when you do not have to rely only on the board for your balance: on a bodyboard you have your legs/fins, on a SUP the paddle, on a wind/kite/wing the sail, and on a skimboard you do not care to stay up, as most turns are finishing maneuvers anyway :-),