I've also used handhelds (Garmin, Lowrance & Megellan) in my private planes and boats. Screen size and being able to read the screen in bright sun (low wing bubble canopy) was an issue to me flying and the Lowrance brand did that way better than any others. It has options for large text/numbers and adjustable contrast. The downside is it eats batteries when setup for best reading. A personal preference to me is the touchpad on bottom instead of on top like Garmins are. It just fits my hands better and lets the screen be in line of sight on front of dash installations. I move it from plane to 3 different boats. On a 20' pontoon boat I use a recessed cup holder to hold the unit and the screen is easy to see. Garmin's have a better data base setup and are easier to page though and access saved waypoints. The Lowrance requires more steps to access the database. It isn't nearly as friendly as a Garmin 12s or other Garmins. Reliability isn't an issue with either but Lowrance probably takes the quality lead. They were the first to use 12 parallel channels too...Garmin's and others followed. My early handheld Lorance will work while sitting in my house. It receives though a drywall ceiling and plywood roof with shingles and only takes a minute or less to lock on the satellites. I tried a Garmin 12 and it wouldn't lock on unless outdoors or close to a window. Either brand is good to go with but Garmin has more to chose from, more accessories and lower prices. Also, on any handheld gps with the tiny display screen it is almost impossible to read maps without the data being very busy and cluttered. Maybe if you're 25 yrs old with perfect eyes that won't be a problem but small maps aren't practical to me. I typically use the "go to" function and put the screen up that plots my tract while showing reference waypoints and navigation. It lets you in zoom in and out and see departure and destination without clutter. For a small boat I wouldn't get bogged down with a large fancy gps unit. For a big boat it would be different. Bill P.