Forgot to mention. At the bottom on the back of the unit is a slat that you can put a lanyard through. My plan is to use a lanyard and tuck it into my life vest for easy access.

I also got the SPOT Communicator which works with my iPhone. It works using Bluetooth and gives me tracking and communication ability. I tested the Communicator on the cruise too. It works good once you figure out the proper steps in resetting the Bluetooth connection. If you preset messages and groups you only have to send text messages when you are in real trouble.