[CRussel]

Listening to books on my new, waterproof, Delphin while swimming in my Endless Pool.

This is a solid 4 3/4 out of 5 for waterproof audio players. I'm still testing out its various features. Here's the details, good and bad. First, the bad:

1. WiFi is supposed to be off while swimming. Doesn't work anyway in the water, so duh. But it's a bit annoying if you need to change something.
2. Sound quality through the plugged in headphones is pretty poor. Totally adequate for books, but I wouldn't want to use it for music. OTOH, they've been totally transparent about that, AND the sound quality through the Bluetooth is much better. For books only? I find the included headphones quite adequate.
3. Button interface is a bit awkward at times, but do-able. However, the addition of a WiFi button would have been a plus.
4. Battery is pretty minimal. And will get worse over time, of course. But it's acceptable.
5. Automatic shutoff after 30 minutes. Might be annoying if you're swimming long distances. Not (yet) configurable.
   ETA: 30 minutes of inactivity, not 30 minutes of playing music or listening to books. So not really a problem.
6. Wireless keyboard included wouldn't pair with device. Quite annoying, actually. But I'm going to send email or call tech support. Good test of their support.
   ETA: Support was great, problem resolved, and their instructions and video being updated to reflect what the support engineer and I discovered.
7. Proprietary charging cable. But it works.

Now, for the good stuff:

1. Light, small, and no hindrance on my goggles headstrap.
2. A BUNCH of ear pieces -- you'll certainly be able to find ones that will fit and keep water out of your ears. So odd shapes there, but they actually work well.
3. Audible app. Native behaviour. Love it. Just love it.
4. Amazon Music for those inclined. Spotify, Pandora, etc, for those of other persuasions. (Requires offline mode, so Premium necessary.)
5. Small screen but usable, just, without extra keyboard.
6. Charges in a reasonable time -- a bit over an hour from nearly dead.
7. No more excuses, no more reason not to swim.
8. Wish I'd bought the 16 GB, but only because I always wish I'd bought more memory.

ETA: I've had this for a month now, and swum with it at least every other day. It's still absolutely the best waterproof music/audiobook device I've ever used, full stop. And it's now available for purchase. (I got mine via Kickstarter.)