weather ship

noun2

1. •
   A ship, usually permanently on station, tasked with reporting meteorological data.
2. •
   A ship to the windward of another; considered an advantage in naval warfare.

   • If the weather ship be of inferior force, it enables her to keep out of action much longer, and, though a poorer sailer, she may do so until the intervention of night increases the chances of escape. — 1832