"Welcome to CLIP - the Crew List Index Project CLIP is a not-for-profit volunteer project, set up to assist research into the records of British merchant seafarers of the late 19th and early 20th century. Over the last twenty years we have worked with hundreds of people and many archives around the world to make the largest database of seafarers' records and provide unique resources which are widely used by maritime researchers." Code: http://www.crewlist.org.uk/#top
I used this site for my Isle of Man seamen. Brilliant; as it shows crews, so often fathers & sons, cousins, in-laws etc. Plus owners, so who was crewing for who. Plus the youngsters adding a year or two onto their age. It gave me a wonderful insight into the community. Also enabled me to find an original ships log at Kew.