Or turn the phone off and the battery lasts forever
But then it's useless for some functions like GPS, which can be very important on large lakes without distinguishing landmarks in view.
Yes, the phone can be tuned on to capture a GPS position.
While I don't sit out there and surf the net while I'm on the lake, I'm now using my phone for autopilot mapping functions and geolocating. Same would go for those using iPads with boating/fishing related applications. Navionics, anyone?
I had a situation a few years ago up in Canada that convinced me that a smart phone wasn't a bad thing out on the water. One evening, a buddy and I decided to go back out after dinner and see if we could get some walleyes since there were a few hours of light left. While we were out on a large open piece of water, smoke blew in from distant fires and visibility dropped to about 2 miles, maybe less. Landmarks disappeared, and I got disoriented. I didn't have a compass, nor did I have a map. After all, I was on a piece of water I had fished many times. What could go wrong? Long story short, I nearly got to spend a long night stuck on the water or beached somewhere, and my colleagues would not have known exactly where I was. I now keep a map, and my phone can provide lat/lon even out of cell range.
