This is, quite simply, the only game in town. It's so dominant that there are books written about the installation of the M802. It’s been honed through the years and now offers the very best combination of features for the cruising sailor. Be sure to add a DSC antenna and GPS lat/long to make best use of the built-in rescue features.
Installing the M802 has become the Mt. Everest of marine electronics. Buy a good book and learn all that you can.