There's also the Amphibious Assault Ships, like the USS Wasp. She has facilities for up to 600 patients, can accommodate a bunch of helicopters on her huge landing deck, and has an internal dock which can hold Air Cushion Landing Craft which can transport supplies and men from the ship all the way onto the beaches.
The Wasp is currently deployed giving assistance to the Leeward Islands, which were also heavily hit
After Irma, Navy Takes On Unusual New Mission In US Virgin Islands: Aid