Seiko Prospex Samurai SRPL15 vs Seiko Prospex SRPL51 Diver

These two are the same Seiko Prospex diver underneath: same 4R35 movement, same 41.7mm case, same 200m rating and Hardlex crystal. The real split is the case finish and weight. The SRPL15's black hard coating and 100g weight make it the lighter, stealthier daily wear. The SRPL51 is a plain stainless steel diver at 170g, with LumiBrite listed on hands, indexes and bezel. Buy the SRPL15 for a lighter, scratch-resistant blacked-out look; buy the SRPL51 for a classic steel diver with a bright bezel lume. Owners of the 4R35 praise its reliability and the 41-hour reserve; the known trade-offs are Hardlex instead of sapphire and accuracy that drifts more than a regulated Swiss movement.

• Choose the Seiko SRPL15 if you want a lighter watch with a black hard-coated case that hides scratches and looks less like a standard steel diver.
• Choose the Seiko SRPL51 if you want a conventional stainless steel diver with LumiBrite on the bezel as well as the dial.