[Mixtape]

This is doubled by the fact that lots of boaters will try to keep their phone as far from the water as possible for safety's sake. In practice, using your phone is better than using nothing at all, but a dedicated waterproof device that you can clip onto your clothes and forget about is by far the better option.

[tempestn]

Most phones these days are pretty water resistant, so you could just keep it in your pocket.

[mcv]

More importantly, if you fall overboard, the value of your phone is probably the least of your worries.

[tempestn]

I don't know about that. If the boat is moving and you're left stranded then yes, of course. If you fall off a stationary boat in warm weather and climb back on though, your destroyed phone might be at the top of the list of concerns. I can see why someone wouldn't want to carry around a non-waterproof phone on a boat. Even if the phone is waterproof (resistant), a zip-up pocket is probably a good idea. Water resistance wouldn't help you much if it's at the bottom of the ocean.