Certina DS Action watches

The Certina DS Action belongs to the brand's Aqua collection and is built around a steel diver with a 60-minute rotating bezel. DS stands for Double Security, the case construction Certina developed in 1959 to protect the movement. Certina describes today's version as a sapphire crystal, an O-ring on the stem, two in the crown, a dedicated caseback gasket and a reinforced caseback.

The DS Action Diver is certified to the ISO 6425 diving standard and rated to 300 m, and Certina tests each one in water for three hours. The Powermatic 80 models run on an automatic ETA calibre developed from the 2824, slowed to 21,600 vph to reach an 80-hour power reserve; in the 38 mm Diver it has a Nivachron balance spring, which Certina says resists magnetism. Since 2017 Certina has supported the Sea Turtle Conservancy, a Florida group founded the same year as the DS concept. The Sea Turtle Conservancy Diver swaps Certina's turtle-shell caseback for the Conservancy's logo and adds blue accents, including the seconds hand.

The Diver Powermatic 80 is a 43 mm watch, also made with a ceramic bezel insert in steel or titanium. The 38 mm Diver (C032.807) is the same idea for smaller wrists and takes a 19 mm strap, and the PreciDrive Diver sits between the two at 41 mm. The Diver Chronograph is a much bigger watch at 45 mm and over, and the GMT Powermatic 80 measures 43.1 mm.

Alongside the Divers sit the 42.5 mm Chronograph with its dive bezel, the Powermatic 80 Day-Date and the 41 mm Quartz. At the small end are the 34.5 mm Powermatic, with mother-of-pearl dials in steel or steel and yellow gold, the 34 mm Lady and the 33.8 mm Diamonds. Several models also come in titanium.