Transcriptions from original documentation
If you'd like to study the original transcriptions direct from the Registration Logs at the various ports, we've them here. The official register had commenced in 1786 and sailing vessels with a deck and over 15 tons had to be registered by law while all, however small, had to be registered if it was intended to sail them to a foreign port. John Collins' guide notes for the information are available 
here
If you spot something which, when using the 'Vessels' database doesn't seem very clear - and there is much work to do to standardise entries - we would recommend you look at John's original transcription in the list below for clarification.
London Foreign Going 1787 to 1799
London Foreign Going 1800 1823
London Foreign Going 1824 to 1835
London Foreign Going 1836 to 1855
London Foreign Going 1855 to 1899