Sangin Instruments Atlas IIIvsSeiko Prospex Sea 1965 Heritage Diver's Watch
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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.

Atlas III

Prospex Sea 1965 Heritage Diver's Watch
Diameter
42mm
40mm
Lug-to-Lug
n/a
46.4mm
Thickness
n/a
13mm
Water Resistance
200m
300m
highest
Power Reserve
n/a
72h
MSRP
$949
lowest
$1,300
Movement
La Joux-Perret G100
Seiko 6R55
Case
6 specsCrystal & Dial
5 specsMovement
3 specsPricing
1 specsReviews
Synthesized for each watch independently from owner discussions, enthusiast forums, written reviews, and video reviewers.
Owners widely praise the Sangin Instruments Atlas III for its great quality and value, with one owner noting it is hundreds of dollars cheaper than alternatives. The watch is reported to be in excellent condition with minor rub marks visible only up close and is keeping very good time. Some owners find the omission of minute indices bothersome, and one owner prefers a different model due to its smaller case size and lug geometry. Overall, owners rate the Sangin Instruments Atlas III highly for its excellent quality and value from a lesser-known company.
Owners widely praise the Seiko Prospex Sea 1965 Heritage Diver's Watch for its refined engineering, comfortable 40mm case, and improved 300m water resistance. The watch is noted for its better build quality and finishing compared to some alternatives, featuring a mix of polished and brushed surfaces, with specific callouts for the jewel-toned teal dial with a rippling-water pattern. Some owners consider the price fair, while others suggest it is too high. Accuracy figures vary, with some owners reporting their 6R55 movement performs well within +/- 10 seconds per day, while others note theirs runs slow or have concerns about QC for the price. The bracelet, while improved, lacks modern features like quick-release or extensive micro-adjustments. Overall, owners and reviewers rate the Seiko Prospex Sea 1965 Heritage Diver's Watch highly for its refined design and build quality at its price point.
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