ais data feed , ip address?

[rgleason]

Agreed Paul, but Marinetraffic with a cell phone is better than nothing when you are in pea soup fog and you hear the fast ferry. Of course there is also radar, but with AIS you probably can get the ship's name to for vhf calls.
Certainly not for navigation or close avoidance in heavy traffic, but still useful.

[Pizzazz]

Best way to go is to replace your radio with a an AIS capable VHF. $350. It integrates well, it is always on, you do not have to mess around with the dongle, PC, power, etc. VHF is one of the few essential nav aids so it makes sense to upgrade.

I have used Marine Traffic with a cell phone connection and it is great for letting others track your progress during coastal passages. Most AIS data has a time stamp, letting you know how long ago it was updated. So if you see data older than 30 sec you know to be more careful. Best aid for collision avoidance is radar and if sailing in congested waters I suggest you get one, even if used or old. Many boats do not transmit AIS. I would not do night sailing in congested waters without radar.