Tony
This might be a red herring - but it looks as if Gibraltar had its own newspaper by 1806.
Quote:
The Gibraltar Chronicle
The Gibraltar Chronicle is unique in the history of Gibraltar and the world of newspapers as the first issue appeared on 14th May 1801 and was owned by a trust of officers of the Gibraltar Garrison; since then, the newspaper has run continuously.
Today the Gibraltar Chronicle is an English newspaper printed locally and overseen by an independent Trust to keep the news unbiased.
The GC might have had detailed info re ship movements - but there again it might not!
The British Newspaper Library only has copies from 1825 but maybe the Gibraltar Historical Archive has a full run.
http://www.gibraltar.gov.gi/gibraltar-archivesObviously don't know how much time/resources you have to put into this quest - but that might be a line of enquiry I would follow if I was really desperate.
As for then searching the musters of all the ships . . . . . . . . . . good luck!