Audemars Piguet Royal Oak Men’s Watch 39MM Gray Stainless Steel 25979ST. 50 m (5 ATM). In honor of the Alinghi victory of the 2003 Americas Cup, the Royal Oak City of Sails is Limited Edition of 1,250 pieces. The stainless steel 40 mm is assembled with luminescent hands and a screw-down crown. The automatic timepiece is powered by a 2385 calibre with a 40-hour power reserve.