Upper Clyde Temporary AIS Fix

Due to a 'blackout' in the AIS signals from the Upper Clyde, the system is now using its 'fix', where a ship passing Dunglass will trigger estimated actual departures and arrivals times (based on historical averages. This is necessary for the rest of the system to understand if a ship has docked or departed from the blacked out region. The fix will be taken off when normal coverage resumes.