I've been a big believer in rod floats for many years. Here's another simple fix that can save $500-$1,000.
Over the years I have tried to teach several cameras and cell phones how to swim.......none of them did very well.
Since I've used my cell phone for pictures the past several years I've found placing a floating case on the phone keeps me from losing it if it falls overboard. I have dropped my phone in the water at least once a year while trying to take a fish picture while on the pontoon.
These cases are now finally being manufactured by a number of reputable firms and they work.
These fit snugly on the phone and are not the plastic bag type things that don't work well and are cumbersome to use.
Also, many phone insurance policies won't replace a lost phone.
Most of the modern smart phones are "watertight" for about an hour at 3' deep, if your phone ends up in the lake or river, reach down, pick it up, and wipe it off. Much better than watching it sink to the bottom.
Here's a link for one manufacturer but shop around the net for "Floating Phone Cases" there are a number of suppliers.