1924  Bater. a beating seal; young migrating seal.
1933  Now [the whitecoats] became the "beaters" of the Seal Hunt, and of certain surety every little head will be pointing for the North.
1966  Baby seals are bought by an English firm and used to make coats; beaters, the harp seals between three weeks and a year old, are bought by a Norwegian firm and used for jackets.