April 14, 2011 13:51
I second what GPSNavX says, but I use my iPad and iNavX as my primary, with a Garmin 441s (and my laptop) as backups. The Garmin has an internal GPS antenna, so installation is simple. You do have to add a transducer, to use the depthsounder feature, but you can use an in-hull that can be installed without hauling the boat from the water. Look at a good marine electronics catalogue to see the large variety of depthsounders available.