 In 1987, "Missouri" was outfitted with 40 mm grenade launchers and 25 mm chain guns and sent to take part in Operation Earnest Will, the escorting of reflagged Kuwaiti oil tankers in the Persian Gulf.These smaller-caliber weapons were installed due to the threat of Iranian-manned, Swedish-made Boghammar cigarette boats operating in the Persian Gulf at the time.On 25 July, the ship departed on a six-month deployment to the Indian Ocean and North Arabian Sea.