(in this case, Naval)
by Carl Kurfess
Make a pass
Flirtatious advance.
When naval ships-of-the-line were sizing each other up they would quite often make a side-on pass, each wishing to size up the opposition. When the expression came ashore, it was used as a tentative approach to a member of the opposite sex to gauge the likely outcome of closer engagement.
(For you detail sensitive types, the two ships at left would actually appear to be Frigates, smaller than Ships of the line. Your friendly sailor editor)