Your story sounds just about like mine. My wife is not too tech savvy but is comfortable with her I-phone and MacBook so that is a good argument to stay with the iphone. The only waterproof phone I have researched is the Kyocera Hydro but I think the reviewers gave it something like 2 or 2-1/2 stars. My son is visiting and has an iphone 5 with a waterproof case that isn't too bulky. Roverhi mentions a couple of other waterproof options that I will look into. I don't have a charting app on my current phone and would only use it as a third or fourth level backup.