Beyond the requisites of a professional diver’s watch (300 metres/1000 feet) this model is water resistant to 600 metres/2000 feet. Other features that distinguish this as a professional diver’s instrument are the screw-in crown and screw-down case back, the helium escape valve, the fluted uni-directional rotating bezel featuring a luminous dot and the highly visible hands on the dial.

Positioned at 10 o’clock and embossed with the chemical symbol for helium “He”, the helium escape valve allows any atoms of this gas to escape during decompression. This is a vital function when using a diving bell, as minuscule helium atoms are able to penetrate the case and could damage the watch when expansion occurs during decompression. The chronograph push-buttons, made of steel and decorated with a coloured aluminium ring, are functional to 600 metres/2000 feet while the domed scratch-resistant sapphire crystal has received an anti-reflective treatment on both sides for optimum clarity.

The matt black dial offers excellent contrast thanks to applied luminous hour markers and the use of Arabic numerals in either white or orange at 12, 3, 6 and 9 o’clock. The date window is positioned between 4 and 5 o’clock. The facetted rhodium-plated arrowhead hour and minute hands have SuperLuminova inserts and a highly visible orange tip further enhances the luminous arrowhead seconds hand. Along with the luminous dot on the bezel, the high visibility of the markers and hands are invaluable for measuring precise dive times, even when descending to the darkest depths of the ocean.

True to the Seamaster’s roots, the Calibre 3313 high-quality self-winding mechanical movement with a power reserve of 52 hours drives the Planet Ocean Chronograph. The Co-Axial escapement, proprietary Omega technology, considerably reduces friction in the heart of the watch mechanism and offers improved long-term reliability and accuracy. A free-sprung balance further improves this COSC-certified chronometer. The column-wheel mechanism serves to perfect the chronograph’s performance. It ensures a smooth start to the sweep of the seconds hands when the chronograph is activated and provides precision stop and reset functions. The rhodium-plated movement has been given a luxurious finish and the bridges are decorated with attractive circular graining, Geneva waves and gold-plated engravings and the screw-down case back features a seahorse medallion.

All three models are available on a comfortable satin finished stainless-steel bracelet with polished sides. The fold over safety clasp is secured with an easy to use release mechanism. These models are also available on a black rubber strap with either white or orange stitching, a plain orange rubber strap or the famous orange alligator strap. All straps incorporate a stainless steel fold over clasp.