Side by side

Marathon Arctic OSAR 36mm AutomaticvsSeiko Prospex Sea

The numbers, the dial colors, the calibers — laid out so you can stop flipping between tabs.

Arctic OSAR 36mm Automatic
MarathonArctic OSAR 36mm Automatic
MSRP $1,200
Prospex Sea
SeikoProspex Sea
MSRP $1,100

At a glance

12 of 29 specs differ
Diameter
Arctic OSAR 36mm Automatic36mm
Prospex Sea41.3mm
Power Reserve
Arctic OSAR 36mm Automatic40h
Prospex Sea72h
Water Resistance
Arctic OSAR 36mm Automatic300m
Prospex Sea300m
MSRP
Arctic OSAR 36mm Automatic$1,200
Prospex Sea$1,100

Full specifications

Case

5 specs
Diameter
36mm
41.3mm
Thickness
13mm
12.5mm
Lug-to-Lug
43.5mm
48.2mm
Lug Width
18mm
20mm
Material
316L Stainless Steel
Stainless Steel

Crystal & Dial

3 specs
AR Coating
Inner
Anti-reflective coating on inner surface
Dial Color
White
Black
Lume
None
LumiBrite on hands, index(es) and bezel

Movement

3 specs
Caliber
Sellita SW220-1
6R55
Power Reserve
40h
72h
Jewels
25
24

Pricing

1 specs
MSRP
$1,200
$1,100

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What people say

Owners + reviewers, side by side

Synthesized for each watch independently from owner discussions, enthusiast forums, written reviews, and video reviewers.

Marathon Arctic OSAR 36mm Automatic

The Marathon Arctic OSAR 36mm Automatic is noted for its non-tritium dial option, though some owners prefer the 1-12 numeral layout found on other models. One owner found the 36mm size too small for their wrist. Overall, owners appreciate the Marathon Arctic OSAR 36mm Automatic for its non-tritium dial option.

Seiko Prospex Sea

Seiko Prospex Sea models are widely praised for their excellent build quality, value for money, and comfortable wearability, with many appreciating the vintage-inspired designs and robust construction. Owners note the silicone straps are surprisingly comfortable and well-finished, and the Lumibrite lume is excellent. However, some find the 44.3mm size and thickness too large for smaller wrists, though others report the sizing as perfect. The 6R15 movement in some variants offers accuracy around +4 seconds per day with a 50-hour power reserve, while newer movements offer more. Some models are criticized for a bracelet width not matching the case size or a rudimentary clasp for their price point. Overall, owners and reviewers rate the Seiko Prospex Sea highly for its impressive case work and finishing at its price point.

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