I've never actually submerged my h2o . In early October, I was lucky enough to be on holiday in a place with a fabulous pool. I did spend time floating about on an air bed reading my h2o and didn't worry at all about it getting wet. Just because I own a Kobo h2o so I was going to do it, dammit. It did get splashed a bit, but I didn't dare put it under the water.
I love it mainly for the lovely big screen, solid build quality, and memory card support. Glad I took it on some water just because I can now say I did.