Navy Petty Officer 2nd Class Giancarlo Vanzzini dons the facemask of his Viper rebreather while participating in Clear Horizon in South Korean waters, Oct. 17, 2016. CH16 is a live-action exercise which enhances cooperation and improves capabilities in mine countermeasures operations, with participating nations South Korea, the United States, Australia, Canada, New Zealand, the Philippines, Thailand, and the United Kingdom. , assigned to Explosive Ordnance Disposal Mobile Unit 1. Navy photo by Petty Officer 2nd Class Daniel Rolston