I have a Garmin 176 (B&W) mounted on the front cross beam of my Inter 17R. The display is about the size of the TackTick tactical digital compass. It is simple to change its orientation to facing port or starboard tack for best visibility, and the large display can be customized with one or four large fields, or a map, or both if desired. It will log miles and elapsed time as well as bread crumb trail on the map. I use it in tacking and jibing drills to review my course from God's eye view. I put it in a zip lock quart bag and then clip it into its bracket and it is waterproof. The supplied bracket mounts easily in the beam track groove with a washer and short bolt, and the unit unclips in seconds. Garmin units use BlueChart cards for complete regional chart coverage; my card covers from Tampa to New Orleans. I've tried digging it out of a pocket or wearing it around my neck on a lanyard, but on a single-handed boat with a chute I don't have a free hand! It's not cheap, but if I ever go open ocean or need to plot a long course, the large display can't be beat.