When launched in 1997, the Aquanaut created a sensation. It was young, modern and unexpected. Its case was a rounded octagon, inspired by that of the Nautilus. And it sported a “tropical” strap, made of a new composite material ultra-resistant to wear, salt water and uv radiation. Aquanaut Travel Time in Steel. Mechanical self-winding movement. Caliber 324 S C FUS. Dual time zone mechanism indicating local and home time. Local and home day/night indications in apertures. Local date by hand. Sweep seconds hand. Dial: black embossed dial. Steel case. Screw-down crown. Sapphire-crystal case back. Water resistant to 120 m. Case diameter (10-4 o'clock): 40.8 mm. Height: 10.2 mm. Black polymer material. Aquanaut fold-over clasp.