Seiko's "Sumo" diving watches have earned a strong following over the years, with clean styling and large, robust cases. The Prospex Sea Solar GMT doesn't reinvent the style, but instead plusses it with a solar-powered GMT movement. The elapsed time bezel remains in place, with a 24-hour scale placed at the edge of the textured dial, working with a local-jumping bright orange GMT hand to tell the time in a second zone. Its Seiko 5K65 solar quartz movement charges via light and offers a nine-month power reserve, operating hour, minute, second, and GMT hands as well as a date window at 3 o'clock. Available in green or blue, the watch sits on a matching steel link bracelet.