If the MarineTraffic Live Map looks like this on your screen...
...there is a good chance that this is caused by AdBlock (browser extension software).
Recently, AdBlock released an update which seems to interfere with Google Maps on MarineTraffic. As a result, the Live Map could disappear altogether.
All you have to do to bring the map back is to disable AdBlock for the MarineTraffic.com domain.
How to do that? Follow the instructions here (by WikiHow).
Note that if you do not wish to completely disable AdBlock, you can easily exclude the MarineTraffic domain from its index:
Simply, click on the "AdBlock" icon on your browser and click on the "Don't run on pages on this domain" option (as shown on the picture below).
A pop-up window will appear - click on the "Exclude" button and you should be good to go (without completely pausing AdBlock)!
Now, you should be able to view the Live Map as usual!
Please use the comments below to tell us if this has worked for you while we will be looking for a permanent workaround!