We’ve referenced the MarineTraffic.com link on this site for a while. It has improved much since we first pointed to it. Since it relies on shore-based receivers porting their received signals to a server, it has holes. Their smart phone app has reached a level of stability it can be very helpful in identifying traffic if you sail were you have 3G coverage (and don’t have your own AIS).
It has had another benefit as well. There is no marine traffic separation scheme in the waters we call home. So big ship tracks tend to the centerline of the ship channel except when meeting. This doesn’t always mean the deepest part of the natural channel. They usually coordinate their meetings for the wide spots in their road.
All this seen from a small boat underway is somewhat opaque. They are just big and fast. But, for several weeks now we have been plotting their tracks and have ended up with a statistical cross-section of the “ship channel” at regular points along its length. The degree to which the pilots keep ships on the centerline is remarkable.
I now have an opportunity to watch this site 24-7 with screen cap software that creates manageable file sizes. With some luck in the next two months, I will have a graphic picture to match the statistical one.
What I have learned from this is a bit of time spent watching the AIS when one doesn’t need to be watching it can reveal things useful when one is later underway.