Welcome to the club!
I'm not a Yamaha fanboy, but I have come to appreciate those boats and how robust the design is.
IMHO, the risks associated with overloading Yamaha jet boat are probably similar as compared to a wake boat.
Except if using bags anywhere in the cockpit - the Yamaha decks and swim platforms are self-draining (w/ a scupper) - brilliant feature.
The Yamaha rub rails leak if you push it really low, but it is not a huge deal, I would always want a secondary bilge pump in any boat used for surfing. If taking water overboard - I would honestly rather be in my AR240 than just about anything else in that size class, as far as being able to overcome being swamped in rough water etc.
Hole shot is not an issue with or without ballast, especially with twin engine Yamahas. Provided some simple mods that can help and general maintenance, everything sealed and ported and no cavitation.
(Just ask
@jcyamaharider about the hole shot of my yammie, lol - last weekend he sent a few things flying off of her... as he likes to stomp on the throttles, lolol)
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