Ok so please don't take this the wrong way but in my experience no one will notice or care.

People have scars. I have a huge one on my stomach that is visible even when I wear a normal T-shirt because I'm just flat out missing a part of it. I've been ashamed and afraid of people noticing for most of my life until I finally realized that literally no one cared.

Scars are something that happen throughout your life. Everyone has a scar somewhere. Go swim. If people ask you about it, and I'm almost certain no one will, just tell them "Oh it doesn't hurt, don't worry about it" and that's that. You don't have to explain your scars.

They're there, they don't hurt and that's that.