Sharpie
The database includes some people travelling from Europe - ie if the voyage began outside Europe but called it at European ports before docking in the UK, then the passenger lists will include the people who came on board at Gibraltar, Lisbon etc
For anyone who hasn't found the people they are looking for, the reason may be that their forenames are not written in full, but only appear as initials, or Mr, Mrs, infant etc. More worrying is the fact that quite a number of names do appear in full on the lists,and are clearly written, but the surnames are not included in the index. Hopefully this will get fixed eventually, but meantime it may be worth searching without a surname in case that brings up the results you want.
Happy hunting.
Mean_genie