The two Mercy-class hospital ships have become prime assets in the Navy's efforts to reach out to foreign countries and provide humanitarian assistance and disaster relief. Since 2001, the hospital ships have conducted a number of humanitarian-assistance and disaster-response missions at home and abroad, providing care to more than 550,000 people.
Comfort, which originally drew most of its medical staff from the Washington area, was transferred to Norfolk, Virginia in 2013 to be closer to the Portsmouth Naval Medical Center, where most of its medical staff now is based. Comfort deployed for 180 days for Continuing Promise 2015. In 2017 Comfort deployed to Puerto Rico to support relief efforts after Hurricane Maria, and in 2018 Comfort deployed to South and Central America for Enduring Promise 2018.
Mercy has made three 150-day deployments in recent years including Pacific Partnership 2015, 2016 and 2018. Comfort also provided humanitarian assistance and disaster relief for Puerto Rico in the wake of Hurricane Maria in 2017.
USNS Mercy (T-AH 19) and USNS Comfort (T-AH 20) each contain 12 fully-equipped operating rooms, a 1,000 bed hospital facility, digital radiological services, a medical laboratory, a pharmacy, an optometry lab, a CAT-scan and two oxygen producing plants. Each ship is equipped with a helicopter deck capable of landing large military helicopters. The ships also have side ports to take on patients at sea. When fully operational, the hospital ships have a crew of about 71 civilians and up to 1,200 Navy medical and communications personnel. The precise crew composition and size varies by mission type. During humanitarian-assistance missions, the crew often includes representatives from other U.S. services, foreign militaries and nongovernmental organizations.
Both hospital ships are converted San Clemente-class super tankers. Mercy was delivered in 1986 and Comfort in 1987. Normally, the ships are kept in a reduced operating status in Norfolk, VA, and San Diego, CA, by a small crew of civil service mariners and active duty Navy medical and support personnel. Each ship can be fully activated and crewed within five days.