Seiko 5KXvsWhitby Watch Co. Ad Mare Diver
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Measurements
Catalog photos are all shot at the same flattering size. These aren't: every case below shares one millimeter scale.

5KX

Ad Mare Diver
Diameter
42.5mm
44mm
Lug-to-Lug
46mm
lowest
50.8mm
Thickness
13.4mm
lowest
14mm
Water Resistance
100m
200m
highest
Power Reserve
41h
highest
38h
MSRP
$350
lowest
$550
Movement
Seiko 4R36
Sellita SW200-1
Case
4 specsCrystal & Dial
3 specsMovement
3 specsPricing
1 specsReviews
Synthesized for each watch independently from owner discussions, enthusiast forums, written reviews, and video reviewers.
Owners widely praise the Seiko 5KX for its strong lume and value, with many reporting accuracy within +/-5 to 10 seconds per day, though some experience +/-1 second. The 42.5mm case is noted to wear smaller, and the watch offers a comfortable feel for many. Some owners are split on the bracelet quality, with opinions ranging from "cheaper side" with hollow links to "flimsy-feeling" jubilee. A few quality control issues have been reported, including a failed bezel clickspring and misaligned components. The Seiko 5KX is seen by some as a worthy successor to the original SKX, offering an upgraded movement with hacking and hand-winding capabilities, though others lament the loss of ISO certification and a screw-down crown. Overall, owners rate the Seiko 5KX highly for its excellent lume and value proposition, making it a popular choice for everyday wear.
Owners widely praise the Whitby Watch Co. Ad Mare Dive Watch as a solid dive watch for its price, with multiple users calling it the best deal under $600 and one rating it 8.5 out of 10. Reviewers note its substantial feel, quality construction, and crisp dial with applied indices, powered by a Sellita SW200-1 automatic movement. Some owners find the 44mm case size to be a comfortable daily wear, with one mentioning the sanded texture of the titanium variant keeps it light. Drawbacks noted by one owner include the absence of a date wheel. Overall, owners and reviewers rate the Whitby Watch Co. Ad Mare Dive Watch highly for its value and build quality at its price point.
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