Originally Posted by Familycruisers
Marine Traffic is an AIS app for Android.
As I said in my prior post, MarineTraffic is not
a navigation quality tool. MarineTraffic uses a network of land-based stations manned by hobbyists at their homes. There can be blackout zones when the stations go down, and there can be time delays in their updates. When a vessel is moving 15 knots up the river, a delay of 4 minutes equates to a nautical mile. That's the difference between being able to tack across the channel and encountering a very uncomfortable situation.
I have confirmed this from side-by-side comparison of my real-time AIS reception with the MarineTraffic app on my phone.
MarineTraffic a nice novelty for looking up pictures and port history of boats, but do not use MarineTraffic for real time navigation!