Word comes today of a FANTASTIC new resource! Lloyds Register of Ships.
This is an online, fully searchable database. The Lloyds list tried to document ALL merchant vessels that were over 100 gross tonnes, self-propelled and sea-faring. Classification of ship didn't matter. The weight and the fact that the ship was sea-going was the criteria.
The registers started in 1764 - almost a full decade before ships lists were required under the Passenger Vessels Acts of 1842 & 1849
The Register tried to document all ships WORLDWIDE. The original registers are with the National Archives in London