I wear a bikini top and board shorts (could put tucking underwear underneath?). It's feminine enough and is not as revealing.

I helped my partner with this and we ended up with a top called a “tankini” which is a bikini top with a light shawl fabric “tank top” that hangs down over your midriff and a “swim skirt” which is essentially a skirt with a bikini bottom sewn in. Usually she just uses that but we also got a swim gaff she uses if we’re gonna do anything but gently swim and float.

She says she feels confident walking around & when her bottom is under the water with it on you’d never be able to see anything. Also, imho it creates a nice look with the top being a bit flow-y blending with the skirt’s pleats. :)

Full disclosure I’m cis and masc so I’m no expert, that’s just what worked for her ymmv!

Swimsuits with skirts are pretty good, and you can always add a gaff if you want.

Leolines on Etsy has a bunch of different swimsuit styles for transfemmes. It's a bit pricey but they make quality stuff.

So a dude here in norway has a trans webshop and the brands I see on there are Nereida and TransMissie/UNTAgG. Unsure what sizes they have available

If you can find a bikini skirt in your size that's probably a good way to avoid future incidents :P

Have you checked Rubies? Rubyshines.com

I haven't tried them but I've heard good things and they seem like a great company.

I have some bikini shorts combos I like. I wear them over bikini bottoms and tuck tape. Plus a sheer coverup I’m generally very comfortable and confident. Gives me options depending on setting, like if I’m just lounging/tanning I can take the shorts off, or walking a public beach I might toss the shorts and cover up on. Some of my favorites are from Prana, but they can be a tad pricey.