“A lien is a lien is a lien, but a maritime lien is not.”
[Gilmore and Black, The Law of Admiralty, 589, 2nd ed. 1975]
It is not necessary to claim a lien on a vessel in order to have that lien. Unlike other liens, a maritime lien can be “secret” and does not need to be recorded. So the crew may have a valid lien (of highest priority) even if they have not recorded a claim of the lien.