Satphone experiences...

Thanks folks...2 old guys in their 70s, that would be me and a friend who owns a 36' Cape Dory will be doing a Gulf of Mexico crossing in a couple of months. My friend is old school. Doesn't use any of the modern navigation methods...just charts and sextant or communication aids other than a VHF radio. I'm good with it as we've done it a few times. This time I told him that having some form of satphone might be a good idea, to which he agreed.