Seiko 5 Sports: day-date or GMT?
SRPD55 and SSK001 solve different display needs.
The SRPD55 uses Seiko’s 4R36 movement with a day/date display. The SSK001 uses the 4R34 and adds a 24-hour hand for dual-time display. Decide whether checking another time zone is part of your normal day. An extra hand is useful only if you understand how to set and read it; follow the exact caliber manual rather than assuming all GMT movements adjust in the same way.
Seiko lists 10 bar water resistance for both, but a sports appearance and rotating bezel do not by themselves establish suitability for scuba diving. Read the activity guidance for the specific watch. Compare thickness, dial legibility and bracelet fit at your own viewing distance. Choose SRPD55 if day/date is the display you need; shortlist SSK001 if a second time display is worth the additional information on the dial. These are task-based recommendations from published specifications, not wear-test scores.
Official references
Original editorial guidance based on linked official specifications and support pages, checked 12 September 2026. Practical checklists are editorial inferences; no hands-on testing or authentication service was performed.
Illustrative official catalog photograph: Rolex Submariner 124060. It shows the catalog model, not a used watch inspected by Watches.red. Image source and credit are recorded in the catalog.