As of this year, the dive-specific Audemars Piguet Royal Oak Offshore Diver is celebrating its sweet sixteenth with a newly updated reference. It spans three new colorways and represents the biggest evolution for the ROO Diver – ROOD? – since the model graduated from being the Offshore Scuba (which originally launched in 2005) to the Audemars Piguet Royal Oak Offshore Diver. The new 2021 models are rocking a more modern movement, tool-less push-button strap changing, and several small but noteworthy design tweaks.To tackle the elephant in the room, no, the size has not changed. The new reference 15720ST retains the 42mm sizing of the standard Audemars Piguet Royal Oak Offshore Diver, along with its uncommon two-crown layout, display caseback, 300 meters of water resistance, and a time/date feature set.ADVERTISEMENTAvailable from launch in “Trailblazing Khaki,” “Navy Blue,” and “Pristine Grey,” each version has a steel case and comes with a second strap so owners can try the new quick-change system right out of the box. The system is fully integrated into the back of the two short intermediate lugs used to match the strap to the case. Simply press the button and release the strap (see the above photo).Audemars Piguet plans to offer a range of straps and, alongside the pair that comes with the watch, the brand already has a trio of calfskin leather straps that conform to the new swappable design.Inside, and forming one of the more major elements of this update, we find Audemars Piguet’s modern caliber 4308, a beautifully finished automatic movement with central seconds, a date display, a rate of 4 Hz, and a power reserve of 60 hours. Visible through the Royal Oak Offshore Diver’s display caseback, the 4308 also featured a black-finished 22k pink gold winding rotor.Other updates include changes to the dial, including new markers and an “AP” signature (in gold) rather than the full brand name common to previous iterations of the ROO Diver.As an exercise in evolving an already successful and qualified design, the new 15720ST looks like a subtle and thoughtful take on the Royal Oak Offshore Diver form. The original black-dial model that was announced in 2010 has long been a dream watch for me, and these new versions look every bit as appealing, especially given the interesting colorways (Pristine Grey for me, please) and the interchangeable straps. Any of the three can be yours as early as May assuming you’ve got $25,400 and a good friend at the boutique. But please – pretty please – just promise me that if you get one, you’ll also take it for a swim every once in a while. After all, you wouldn’t want to be rude with your ROOD, right?