I do nothing special when going swimming - just put my bathing costume on and go in the water. As vette guy said, some people like to picture frame their wafer with waterproof tape - others get out of the water and use a hair dryer on it's lowest setting to dry the wafer (not always practical!). Others do nothing at all and are fine.
Try soaking in a bathtub for 1/2 hour before going on your trip. This will show whether your current bag is up to the job. :)
Good luck and enjoy your trip.
I have had an ileostomy for 31 years now due to UC.
Moderator of the Ostomy Forum
I'm not a complete idiot - some parts of me are missing!