Let me be your salty dog or I won't be your girl at all

In the U.S. Marines and Navy, one who is a salty dog is one who is very experienced, having travelled much and seen more than his fair share of things, used more in the lower enlisted ranks to establish some kind of credibility regardless of rank.

Salty dog also means ornery, as in the T-Bone Walker tune "Ain't Salty No More." Salty dog has an older sexual meaning in US folklore and song. See, for example, the traditional song "Salty Dog Blues", where the lyric "let me be your salty dog" translates to let me be your sexual partner. The term comes from the term sea dog, or a horny sailor.

Avast, ye squirts.

Dear Word Detective: After embarking on Treasure Island, my 6th grade English class began to question the origin of the phrases "old salt," "salty dog," and "sea biscuit." Please help me look like an English teacher who knows everything. -- J. Gabriele, via the internet.

By "embarking on Treasure Island," I certainly hope you mean that your class is reading the novel by Robert Louis Stevenson, and not that you have marooned your pupils on a remote sandbar somewhere. Being stranded on a small island would, no doubt, prove to be a learning experience for the little tykes, but I'm afraid that our namby-pamby liability laws would make such an adventure legally inadvisable. I'd stick to "Gilligan's Island" reruns if I were you.

Still, there's no law (yet) against doing your best to recreate an authentic shipboard atmosphere right there in your classroom, and with sufficient ingenuity you can have those little tars manning the yardarms and swabbing the deck before the weekend.

All the terms you mention date back, of course, to the days of tall-rigger sailing ships. An "old salt" is simply an older sailor with a lifetime of experience aboard ship, well-versed in the skills of seamanship and often also described as "crusty" (which is usually just a euphemism for "cranky"). "Salt" has been used as a synonym for "experienced sailor" since the mid-1800s by allusion to salt water and the salt spray which covers everything aboard ship.

"Salty dog" means essentially the same thing as "old salt," a veteran and often aging sailor. "Salty dog" is probably based on another term, "sea dog," again meaning a sailor with years of experience. The term "sea-dog," by the way, originally was applied to the seals sailors often encountered.

"Sea biscuits," also known as "hardtack," were small biscuits baked without salt, designed to be stored for months in barrels aboard ship. Two further facts about sea biscuits bear mentioning: they were, as you might imagine, unbelievably hard, and sailors encountered them at nearly every meal. Sea biscuits were probably one of the reasons those "old salts" were often so cranky.

Salty Dog Blues

Lyrics: Traditional/Morris Brothers
Music: Traditional/Morris Brothers

Played by Jerry Garcia with the Black Mountain Boys in March 1964, and before that by the Hart Valley Drifters in November 1962.

Roots
The origins of this song are unclear, although the bluegrass version that Jerry Garcia sang was based on the Morris Brothers' version, later popularised by Flatt and Scruggs

The term "salty dog" crops up in various old blues and jazz songs. The first recorded version seems to have been by Papa Charlie Jackson in 1924. He also recorded it with Freddie Kappard and his Jazz Cardinals in 1926 with lyrics:

Scaredest I ever been in my life
Uncle Bud like like to caught me kissing his wife
You salty dog
Oh mama, you salty dog

God made a woman, he made her mighty funny
Made lips around her mouth, sweeter than honey
You salty dog
Oh mama, you salty dog

The Morris Brothers wrote their version in 1935, seemingly independently of the earlier blues versions - though they may have taken what was a public domain song, modified it and copyrighted it as their own. According to Wiley Morris, "Back when we were kids down in Old Fort we would see a girl we liked and say 'I'd like to be her salty dog.'" Zeke Morris had a different version of the origins: ""I got the idea when we went to a little old honky tonk just outside of Canton. ... We got in there after the show and got to drinking that beer and playing the slot machines with nickels, dimes and quarters. I think we hit three or four jackpots. ... The name of that place was the Salty Dog, and that's where I got the idea for the song.

The Morris Brothers version became a bluegrass standard, recorded by Flatt and Scruggs in 1951 and by many others. It is that version that seems to be the origin of what Jerry Garcia played with the Black Mountain Boys. The lyrics that Garcia sang were essentially identical to the main Flatt and Scruggs version - though they did at times sing additional lyrics