About the Zenith 95.9602.3620/51.I303
The Zenith Defy Extreme Diver Topper Edition 95.9602.3620/51.I303 debuted in 2025 as a limited edition of 50 pieces created in collaboration with Topper Jewelers. The watch is based on the Defy Extreme Diver platform and is constructed in titanium. The case measures 42.5 millimetres in diameter and approximately 15 millimetres in thickness. It features a screw-down crown protected by integrated crown guards, a sapphire crystal on the front, a sapphire exhibition case back, and a stated water-resistance rating of 600 metres, corresponding to 60 ATM. The model complies with ISO 6425 standards for professional diver’s watches, including requirements for shock resistance and paramagnetic performance.
The dial is executed in a blue wave pattern developed exclusively for this edition. It incorporates a luminous bioluminescent effect achieved through the application of Super-LumiNova, referencing the natural phenomenon of deep-sea bioluminescence. The dial is paired with a blue ceramic bezel insert and features rhodium-plated, faceted hands and markers treated with Super-LumiNova X1. Time indication is provided through central hours, minutes, and a central seconds hand.
Powering the watch is the El Primero 3620 SC automatic movement, a high-frequency calibre developed without a date function for this configuration. It operates at 36,000 vibrations per hour, corresponding to 5 hertz, and delivers a power reserve of approximately 60 hours. The movement architecture is visible through the sapphire case back and is fitted with a distinctive blue oscillating weight. The calibre displays hours and minutes centrally, with a centrally mounted seconds hand.
The watch is equipped with Zenith’s interchangeable strap system and is delivered with multiple wearing options, designed to accommodate use both above and below a wetsuit.