Audemars Piguet Royal Oak Offshore Black Dial 42mm 15710ST.OO.A002CA.01

Purpose-Built Offshore Diver

The 15710ST is not a chronograph wearing a dive rating — it is a dedicated dive watch. The case drops to 42mm and 14.1mm thick, loses the chronograph pushers entirely, and gains an inner rotating bezel operated through a second crown at 10 o’clock. Water resistance jumps from the standard Offshore 100m to a proper 300m, meeting ISO 6425 dive watch requirements.

Without crown guards or pusher cutouts, the case silhouette is noticeably cleaner than the 26400 or 26401 chronographs. The octagonal bezel with eight hexagonal screws remains — that is non-negotiable Offshore DNA — but the overall proportions are tighter. The newer 15720ST diver updated the case shape and movement, but the 15710ST with its caliber 3120 remains the original Offshore tool watch.

Caliber 3120 and Dive Functionality

The caliber 3120 is AP’s workhorse automatic — 40 jewels, 21,600 vph, 60 hours of power reserve. No chronograph complication means a thinner movement and longer reserve than the 3126/3840. The 60-hour figure is practical: leave the watch off for two and a half days and it keeps running. For a dive watch worn in rotation, that matters.

The inner rotating bezel displays elapsed minutes through a sapphire crystal window. Turning the crown at 10 o’clock rotates the bezel ring, and the system only moves counter-clockwise for safety — an accidental bump will only shorten your recorded dive time, never extend it. Luminous material on the hands, hour markers, and bezel triangle provides underwater readability.

This replica royal oak offshore 15710ST reproduces the dive bezel mechanism, the 300m case construction, and the correct dial layout. View the full Offshore range or reach out via the contact page with questions about this reference.