I'm Marsha.....and I had a way different experience....but that was more than 25 years ago, before I started using the disposable wafers & bags. I had a plastic wafer, that needed the bonding cement, and it adheared to the body quite well. I swam and showered and still was able to keep it on for nearly a week.
Was in Israel for a tour (1990?) was excited about the dead sea experience....knew not to swallow the water, or get it in my eyes. Got up to my knees, and just like PB said....I floated like a cork,
it's impossible to walk in it....but floating was fabulous. Alll was well, got out, did the mud rub...went to the showers to get rid of the mud, and then went into a dressing room with my change of clothes, and pulled down my bathing suit...and everything...and I do mean everthing, fell off! WHAT A MESS! There I was, in the changing room, without access to the shower, covered with muddy "poop".@#$%^&^
But I didn't fall apart, or start to cry. I called for a friend ( who knew about my surgery). She brought me wads of wet paper towels, and plastic bags. I cleaned myself off in the changing room, bagged the SH-T, wrapped myself in a towel, sans appliance....got to the shower....cleaned the reusable pouch....cleaned of the plastic wafer...all while covering the stoma & catching the "flow". I finally made it to a toilet stall ( with a cup of water & supplies) , and managed to change.
The experience is probably what turned me grey early....but I have to say it prepared me for any possibility.. Ironically, I've had "leaks", but have only had my appliance fall off twice in 50+ years. Since then, I've swam in oceans, all over the world, and snorkeled on the great barrier reef. I'm told that there "might" be a problem, if I went scuba diving, and went too deep.. Things can "pop" off ? I haven't had the opportunity ( as yet) to find out the answer to that question.
Have a wonderful trip.....enjoy the Dead Sea....bring "Tape", and drink plenty of water...