Wendy - This is sometimes a topic for debate, but I would suggest you also invest in a handheld VHF, in a dry bag as well. Reason is a distress call from a VHF can be picked by many boats in the area and help can get there quicker, while a cell phone is only point to point - and the person you called must then find help for you. Also, most VHF radios have weather on them, so you can pick up advisories. Just an idea...