Limitations:
This map shows all vessels in range of various independent receivers around the area displayed via Marine Traffic servers. SoC nor Marine Traffic have control over the broadcasting unless you want to set up your own receiver (see there site MarineTraffic.com for more details).
Some areas are not covered at all due to land mass obstructing a view or lack of a receiver in that area. Receivers are also not always turned on so ships signals may dip in and our or may not be available at all. Clicking a vessel will display the last reported time it was seen at that particular location. Generally it is only a minuet or two out from real time but occasionally it can be much more, especially if the ships image is a faded colour.

Sorry, there is nothing we can do to get rid of the Google Adverts on the map. This does however support Marine Traffic and there information.