White hull stripe?

A few pictures seem to show a white stripe running the length of the hull. One taken circa 1911 clearly shows it. But no drawings or diagrams show it. Titanic Research and Modelling Association also doesn't mention it. It also looks like the stripe on Mauretania and Lusitania.

Mar 18, 2008
They did not have a white line (as Cunard Ships). The photo was taken in April 1912 of Olympic and the painting process had not been finished at that stage. The white "line" is nothing more than the original paint from her launch. (There is some debate about the true colour of which it seems was light grey and not white.)