My bathing suit is the bomb for ostomates, because it has two layers. The under layer is a one-piece suit, and the top layer is a halter black mini dress. My bag could puff up to maximum capacity and no-one would ever notice!
If you can't find one like that, do an online search (like on eBay) for 2 pc tankini swim suit, and you'll find a variety of suits that are great. Make sure to get one with skirt, because it hides the poofy pouch really well! If you find one that's New with Tags and can Buy It Now, you'll have it in time for your vacation.
I live in Florida and swim all the time--in chlorine swimming pools, at waterparks, and in the salty ocean--and have never had a problem. With the right suit, you'll be able to enjoy the beach with your hubby!
Dx'd Crohn's in '99 at age 28. Proctocolectomy and ileostomy in '06.
Disease-free and medicine-free since surgery and very thankful to be healthy again.