What time is it?

You can get a digital water resistant wristwatch at Wallyworld for $6-$10. They actually do a great job. If you need to be off the water at a certain time set the alarm.
I've had mine for 3 years now and it shows no sign of crapping out.
If something happens to it you aren't out but a coupe of bucks. It also saves you from losing your cell phone. Like Chadrock said, little to zero reception OTW means better left in the car.
Just have a VHF with you and you are fine.

I just listen to The Weather reports on my VHF not exact time but close enough for me. 

I just got the clip watch from REI today. It seems pretty good but I have some concern about some fumbling with the tiny buttons on the sides and part of the attachment point seems a bit weak. Only time will tell.

well, an hour on the water... went to check the time and was surprised to only find the clip!  I was lucky that it didn't drop down a scupper.

Bummer!  That is exactly the spot i was worried about!  Perhaps some rubberized super glue in the injection joint as a preventative measure on mine.   At least since its from REI you can return it for your money.

I went to the screen on my FF/GPS that allows me to choose the different things that display on top of the sonar screen. Speed, position, temp, time/date etc. I turned on the time/date display. It doesn't show on every screen, but it is there for the one I use most. It also has a timer function which would work for checking crab pots.

  At least since its from REI you can return it for your money.

  almost forgot about  their return policy.   just got a replacement,  now I need to make it more robust. I think it snapped because it got bent too far.

Here's another option for $12.99 at Big5.  A S&W tacticool clip watch.  I like this one because it doesn't have a "joint" which can break.  The downside is it is heavier because it's all metal.  Not sure how long it will last in the salt though.  Even has a LED light at the top!