Old soak

What does it mean if one says to another, "YOU WERE AN OLD SOAK AT THAT". Is this a navy term for something? I heard it being spoken by ex-royal navy people jokingly.

The meaning in the New World is Old Sot, Old Toper, Old Boozer. Here, perhaps, "You sure used to soak it up."
SS

Traditionally, drinking and navies go together. All that grog, you know. Introduction of a grog ration (rum and water) aboard ship was a reform; before that, the drink was straight rum. Old song: "What shall we do with the drunken sailor..." ~rb