Water flumes count in terms of massive amounts of water, which leads to her having a good point related to roller coasters if they have water ponds around or just plain rocky areas. Then there's all the feet around. But don't forget other amusement park rides. I mention in Hearing Aids vs Humans of my being on a roller coaster and in Growing up Deaf - Part 7, the hearing aid encounters the toilet...
We've never seen a fish wear a hearing aid, so we know we can't tuna fish (tune a fish). Just make sure the hearing aid never makes it to the bathroom, either worn or unworn. You do know what Part 7 said above...? A flush is all it takes to lose the thing.
And the final thing you never want to see your hearing aid is heading at high speed away from you, shot from something like a slingshot or a projectile weapon. Its final destination could be in massive amounts of water, somewhere between a rock and a hard place, smack in the grille of a speeding Mack truck, or part of someone's BBQ.
The same thing can easily apply to the cochlear implant's external part.