I want to be on the swim team but am uncomfortable wearing women's swimsuits

Ask the coach. But you'll probably just have to deal with it.

Teams have uniforms. That's why the baseball team doesn't have players in sweat pants and tee shirts.

Most of the boy's swim team suits I've seen are teeny tiny Speedo things, not the baggy trunks most boys wear for swimming. They usually look just like a womans bikini bottom.

Why would the coach let you wear something that will degrade your performance?

Deal with your body shame no matter what you do, but if you want to join then join.

That which does not kill us makes us stronger.

She's female.

I know.

She didn't want to wear the women's suit and the boy's suits don't look too different from the women's suits. It sounded to me like she wanted to wear a typical baggier boy suit but I've never seen a swim team that wore that kind of thing.

For any team sport, you are required to wear the team uniform no matter the sport. It is unlikely your coach will even have a say on whether you could wear something else. Usually whatever league you are competing in whether it high school sports, or other travel type league - they require each team to have a team uniform meeting certain criteau.

I'd suggest wearing a similar swim suit while you practice and swim to get comfortable in it. The more you wear it the more comfortable and natural it will feel. On the bright side - once you get comfortable with wearing the swimsuit, you will actually swim faster as the suit is less resitant in the water than swim trunks and a shirt.