Prospex SPB101J1

The Seiko Prospex Sea SPB101J1 is a professional diver’s watch designed to balance rugged reliability with refined craftsmanship. Powered by the Caliber 6R35 automatic movement, it offers both manual winding and a generous 70-hour power reserve, with 24 jewels ensuring smooth performance and precision rated at +25 to -15 seconds per day.

Its stainless steel case measures 11 mm thick, 37 mm in diameter, and 47.6 mm lug-to-lug, giving it a solid yet wearable profile. A sapphire crystal protects the dial, enhanced with LumiBrite on the hands, indexes, and bezel for excellent legibility underwater or in low light.

The watch features a three-fold clasp with secure lock, push-button release, and extender, making it practical for diving use. At 188 g, it feels substantial without being cumbersome, and the 20 mm lug width allows easy strap changes. Built with a unidirectional rotating bezel, screw-down crown, and screw case back, the SPB101J1 embodies Seiko’s Prospex spirit, durable, precise, and ready for any adventure at sea or on land.