You are my kind of gal! Hi, I'm Marsha, and I have had my ileostomy for more than 50 years, since I was 15... I'm 67 now! Lucky you, in California with all that surfing. I grew up in Brooklyn, swam in Coney Island, but we weren't allowed to have surfboards.... or even boogie boards, if they existed back then.
But once I healed, I was back on the beach and swimming in the ocean. There are some differences between an ileostomy and colostomy.... Not sure if you wear a regular wafer, or if you irrigate (and are predictable, wear a stoma cap). Ileostomy pouches have a plastic rim that actually protects the stoma if you fall flat on your belly.
You can't imagine how lucky you are to have the supplies that are available today.... as compared to the old rubber pouches and hard plastic wafers, and flammable glue I used back in the day. Over the years, since the supplies became better and disposable, I did all kinds of things.... swam in the Dead Sea in Israel where my appliance popped off because of the water pressure. I survived, I think that's the worst thing that's ever happened. It was a bit of a mess, but didn't stop me from snorkeling other places around the world... Carib, Great Barrier Reef in Australia. I used to wear a belt, hooked to my wafer, but found it pulled the wafer up. I've also worn lightweight panties under my bathing suit for extra support, but then switched to bathing suits that have that built-in. I always tape the wafer to my skin (use Scanpore, which is like a second skin) but I understand that there's a waterproof tape on the market. Not good for me because of an allergy, but it might be something you'd try. The wetsuit should give you enough support/protection, but there are stoma guards available, although they seem bulky to me. If you're not sure about the supplies you use, do what was suggested, contact other companies for free samples. Best of luck to you. Let us know how it goes....
Marsha