You don't want both dying for the same reason at the same time. We've used both a Garmin 50 and a Magellan GPS 5000 for years. Also, get the cigarette lighter adapter if you have a 12 volt battery onboard. Finally, remember, electonics and salt water don't mix too well so keeps yours well protected even if the maker says its waterproof. Better safe than sorry.
Newer model are considerably smaller.
Today we'd like to talk about sea anchors and why we carry one. Though not absolutely necessary for the short offshore passages we make from island to island, we do bring one along just on the occasion that we might encounter severe weather or we need to check our drift. Though we have never used ours yet in a official capacity, we carry one as part of our emergency equipement. Parachute Anchor which is good for boats up to 25 feet. When we tested this anchor in the Bahamas in 30 knot winds and 5 foot seas in the Exumas, we found that it stopped Little Cruiser's drift entirely, and it kept us nicely headed into the oncoming seas.