I have upgraded the map again! Now the map by default shows:

ALL ships with imo numbers that are:

In the Forth and Clyde zones
All ships bound for the Forth and Clyde
All vessels in the Calmac fleet.

The above is only constrained by the limits of AIS itself, what the ships send, if their AIS is turned on, and what the AIS feed itself can see (there are black spots in certain areas, like Islay)

So you will see ALL of these by default

You can then toggle to the Calmac only box, zoom out and you will see every Calmac vessel no matter where she is (working her routes, in repairs etc etc) within the bounds of AVAILABLE AIS.

I hope this is an upgrade that gives pleasure to Calmac's devoted enthusiasts as well as Calmac crews and families.