I got three masts: 83 - 91.5 - 100 cm.
The 83 is NEVER used in waves, only in really light onshore winds as for me, impossible to ride in waves, compared.
And yes, I have been out on the 83 in waves and big chop many times, by coincidence - not fun
The 91.5 cm is good allround and used a lot, but mostly so it can be rigged on another board so I dont have to change, as I still prefer the 100 cm in general, at least when windy, 12 knots and above and if waves/chop.
But when small waves riding with low water sand banks, the 91.5 will do just fine - even though it does not matter that much, as you hardly ever ride on the surface here (you will often run aground then, even with the shorter ones, so a no no to go down and a good exercise keeping flight on always here).
Must say, I dont feel the shorter ones to be more agile even if they should be in theory maybe - in fact, the extreme cautiousness you need in order not to ventilate or catch an edge (or even worse, the board goes partly down on the surface), makes it much harder to use and I feel hugely restrained in terms of liveliness because of this, with just a tad shorter mast
Maybe I am simply not sufficiently talented, to ride shorter masts, I know
Back to the topic, racers use around 110 almost all of them, much better when heeled over upwind, and in waves and chop it goes without saying it is better.
Some freeriders, especially those jumping, also like the +100 cm masts.
The difficulty though, is they are not easily obtainable, for a good reason, as the market is really small I think.
Someone like me, am not in the target group for a longer mast, and the race gear is quite specific and not aimed for freeriders - so there is not much offered from the brands above 100 cm.
100 to 115 cm is what I see racers use, but a totally different breed so can not be compared to freeride and waves.
But in some wave conditions it might work better with +100, true.
PF