Actually, it's "United States, arriving" preceeded by striking the ships bell 8 times and done when the President's foot hits the deck.
Which brings to mind an old sea story of mine. I was standing in port Officer of the Deck Watch on my destroyer when we received word that the commanding officer of a cruiser moored nearby was coming on board. My Boatswain Mate of the Watch was brand new, this was his first watch as BMOW, and a little on the dense side to begin with. So I took him aside and made sure that he knew what was expected. Captains are identified by the name of their ship, I remined him. They rate four strikes of the ships bell and then the arrival message. It will go like this, "Ding-ding...ding-ding...Virginia arriving." I walked him through this three times, imitating the striking of the bell and the proper cadence, making sure he knew what was expected. He assured me that he had it down. So the big moment arrives, I'm at the head of the brow, ready to return the salure, and the moment his foot hit the deck I heard the hum of the 1MC and the strong, confident voice of my Boatswain Mate as he said, "Ding-ding...ding-ding...Virginia arriving."