Wouldn't ya know?
The "historical" slang term for anchor was 'mud hook'
And - the older spelling of Brigantine was brigandine - I'd occasionally seen this - and yes, it DOES in fact derive from Brigand! Wow. Fun. It was indeedy the vessel of choice for piracy on the high seas - being highly maneuverable.
Oh yes, we are floating at the moment...me, because I love my job, and the characters, because they are in a bit of a wet predicament.