"Dallas" served as a patrol vessel for the 1977 America's Cup Regatta out of Newport, Rhode Island. In September 1978, "Dallas" joined the search on Georges Bank for "Captain Cosmo", a fishing vessel out of Gloucester, Massachusetts. "Dallas" encountered seas during that search as high as the bridge wings, the decks of which are 38 feet from the waterline. "Dallas" also came upon the "Queen Elizabeth 2" on that patrol, which reported taking a rogue wave over the bow that cracked windows on the bridge. The "Captain Cosmo" was lost with all hands in high seas.