Not being in possession of narcotics for distribution. Unprepared for transaction. Not having the product of choice to sell.
Bill: "Man you got a dub?"
Bob: "Naw, man. I'm not on deck right now"
Bill: "When will you be"
Bob: "Prolly later on tonight"
Bill: "OK. Call me"
To search, look for or seek out something.
Andy: "Man you on deck now"
Rob: "Nope, I can surf and hit you back later"
Andy: "OK, Later"