The AIS unit just makes the data available. What software you use to read/display it will depend on the user if its connected to a PC. If it's connected to a plotter it will depend on the software of the plotter. We are using Coastal Explorer on our PC and AIS has really only been an active player in the last year or so. CE will need to make some changes/upgrades to its software as I expect all the other Nav program players. The easiest way that I see to use it with CE is just let it display the AIS targets and their mouse trails with a short projections of their path. This way they scale with the chart being displayed.....i.e. if you are on a 3 mile chart size it only displays those targets with the displayed chart range. You can always bring up a window that will display all the targets in a list sorted however you would like. So as this all develops I think we'll see different manufactures take slightly different approaches to the display of this info. Colors can come into play for higher threat CPA vs. those of a lower threat for example or perhaps a faster flash rate, etc. If every one in the Med rally had one then they all would see each other all the time on their plotters with a precision and knowledge of exactly who was where. Radar can't do this for you nor can visual sightings at 15 miles on our size boats but AIS can. Target discrimination of two close targets on radar will no longer be ambiguous as to which is which for a few scans while you plot their courses. You've seen the target on AIS long before the radar has, know its heading, speed, call sign and name. Some time later it will appear on the radar and eventually become visible to you. We had an AIS target at 42 miles coming to St Martin. The CE showed a CPA ranging from 0 to .5 miles and a time to CPA of 6 hours. He would be overtaking us from the port stern. 333 meters in length at a speed of 15.1 kts. At 23 miles we had him on the radar but were already anticipating this one. At 14 miles we had him visually but only because we knew exactly where to look and what to look for. At 5 miles with a CPA of 0 to .5 miles we called him on the VHF. He had us on his AIS at 15 miles and said that he would pass in front of us by 1/4 mile. I responded that we'd slow down a kt and give him a bit more room! Interestingly he had us visually before we were on his radar as the AIS showed him where to look for us vs. the watch stander just making the usual horizon scan. With a 1000' length, 200' beam and showing 30' of unleadened draft he was empty and heading for Saint Eustatia for a load of oil. Again we knew his destination from the AIS. We crossed his prop wash a 1/2 mile astern. So my point is that the AIS provides a very useful first notice of something out there. It is comforting to know what it is, its course and heading long before the radar/watch stander sees it. The fewer targets that we need to deal with that appear in close ranges due to visibility or poor radar returns the better I like it. AIS adds this early identification to the mix of tools we have to do just that. For a couple of hundred bucks you can get a receiver, plug it into a PC running someone's Nav software and voila you'll be hooked, IMHO, bugs and all!! As always YMMV.... Cheer Dave & Nancy Swan Song Roughwater 58 Caribbean Cruise '07