NORTHERN CALIFORNIA A U.S. Navy Diver assigned to Naval Special Warfare Logistics Support Unit 1 (LOGSU-1) swims on the surface during a high-altitude dive. The exercise organized by LOGSU-1 is designed to qualify and maintain Naval Special Warfare personnel's altitude diving proficiency and provide opportunities for instructorqualification. (U.S. Navy photo by Mass Communication Specialist 2nd Class Alex Perlman)