Audemars Piguet Royal Oak Offshore Men’s Watch 43MM Stainless Steel Black Rubber 26420SO. 100 m (10 ATM). The Royal Oak Offshore Chronograph is the sports watch that speaks to the luxurious quality that Audemars Piguet is known for. The 43 mm stainless steel case is assembled with a ceramic bezel and 40 jewels. Powered by the self-winding 4401 calibre, this timepiece has a 70-hour power reserve and water resistance of 328 feet.