Seiko Epson YM87

Quartz yacht-timer movement documented as YM87A, with chronograph, a countdown timer set to ten minutes, yacht timer, alarm and date calendar. It has small running seconds at 9 o’clock, small watch hour/minute hands at 12 o’clock and a mode hand at 6 o’clock. The chronograph measures up to twelve hours in 1/5-second increments; in chronograph mode the small-watch hands display elapsed hours and minutes. Yacht countdown presets are five, six and ten minutes, followed automatically by chronograph timing. Casing diameter is 27.0 mm and height including battery is 3.70 mm. Uses SR927W, with approximately three years of battery life under the specified multi-function duty cycle and ±20 seconds per month.