British sailors were called “Jack-Tar” or simply “Tar” because their ships used tar as a waterprof sealant for the decks, bulkheads and just about anything. The black, sticky stuff got everywhere. Hands, clothing and they just got used to it and ignored it. Kind of simular to auto mechanics being called “grease monkeys”
Great song, it’s from “HMS Pinafore” by Gilbert and Sullivan. A light opera of lass who loved a sailor.
Sallah also sings another snatch from that musical, after he gets a kiss listen closely, he sings “I am the monarch of the sea, ruler of the king’s navy…” This was sung by a charactor of Sir Joseph Porter from the same musical. Find this at your library, You’ll love it.