So you turn up to the waterpark in your speedos and they say it's not allowed, but you say I identify as a woman and I'm wearing bikini bottoms.

But they throw you out because women can't go topless. :)

Stringy Bikini Bottoms
 

My itsy-bitsy stringy bottom doesn't work to well on water slides guys

I wear boy shorts swim bottoms with my bikini bra to go down water slides or just swim at the water park in a onesie

Why don't you guys just wear mens onesies like this one

https://www.bodywearstore.com/en/sho...y-105892-navy/

The weird thing about that, is that it draws more attention to your package than swim briefs.

If that wrestling suit is your thing go for it. Wear what you are comfortable and confident to wear. For me it’s a speedo style suit when at the pool , beach or water park.