On November 26, 1984 "Mesquite" sailed from Charlevoix bound for Grenada. Operation Urgent Fury, the United States invasion of Grenada had been launched the previous month. She reached Grenada on December 25, 1984 via Halifax, Bermuda, and San Juan. Her primary mission was law enforcement patrols, but it became clear her services were not needed in Grenada. She headed back to Miami about February 1, 1985. She participated in a number of drug seizures and humanitarian missions while in Florida waters. She met USCGC "Gallatin" towing a fishing boat loaded with of marijuana, which she had seized. "Mesquite" took up the tow, and turned the contraband and the six-man crew over to law enforcement authorities in Miami. She returned to Charlevoix on April 7, 1985, just in time to begin her usual task of resetting buoys in the spring. The ship also deployed to Florida waters during the winter of 19881989 for law enforcement duties. She boarded twenty vessels while on patrol. She arrived back in Charlevoix on April 5, 1989, in time to replace her buoys.