The Admiralty used Great Harbour Greenock for many types of vessel, and also RMAS vessels. They used to have barges for raising sunken submarines. Also to be seen were the weather ships such as Weather Reporter and Admiral Beaufort. They were converted WW2 corvettes.
The ship in the foreground looks like a Clan Line vessel. Also to be seen is a boom defence ship. Ships carrying sugar from the West Indies used to dock there, unloading cargo for the Greenock sugar factory. Sugar line and Harrisons were frequent visitors. Those were the days.