[McGillicuddy]

I recently bought a unit with an external antenna for similar concerns, but in hindsight, I think I'd have been just as pleased with an internal antenna version. One more connection and wire to hide. I believe Bushwacker mentioned he has an external gps antenna mounted in his cuddy cabin and it does fine. Keep in mind your signal is coming from numerous satellites thus numerous celestial tangents. Rarely is the satellite right above you.