Side by side

Seestern S450 Ocean StarvsGrand Seiko SBGR321

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

S450 Ocean Star
SeesternS450 Ocean Star
MSRP $299
SBGR321
Grand SeikoSBGR321
MSRP $5,200

At a glance

13 of 29 specs differ
Diameter
S450 Ocean Star40mm
SBGR32140mm
Power Reserve
S450 Ocean Star41h
SBGR32172h
Water Resistance
S450 Ocean Star100m
SBGR321100m
MSRP
S450 Ocean Star$299
SBGR321$5,200

Full specifications

Case

4 specs
Category
Diver
Dress
Thickness
12mm
13mm
Lug-to-Lug
48mm
46.6mm
Material
316L Stainless Steel
Stainless Steel

Crystal & Dial

3 specs
AR Coating
Inner
Yes
Dial Color
White
Black
Lume
Tritium
None

Movement

5 specs
Caliber
TMI NH35A
9S65
Beat Rate
21,600 vph
28,800 vph
Power Reserve
41h
72h
Jewels
24
25
Complications
GMT, Date
None

Pricing

1 specs
MSRP
$299
$5,200

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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.

Seestern S450 Ocean Star

Owners widely praise the Seestern S450 Ocean Star's Yachtmaster-style case and flawless bracelet finishing, with one owner noting the ST2130 movement keeps good time. The bezel action is described as having individual notches but feeling like a friction bezel, while another owner flags the bezel and crown action as smooth with perfect alignment. Lume is a point of contention, with one source describing it as a nice cool blue with ice-white application, while others note it as weak or not matching Prospex standards, despite using BGW-9. The watch is considered a "big boy" ideal for larger wrists (19cm+), potentially too large for 17cm wrists due to its size and non-tapering bracelet. Overall, owners rate the Seestern S450 Ocean Star highly for its build quality and finishing at the price point, despite some reservations about its size and lume intensity.

Grand Seiko SBGR321

Grand Seiko SBGR321 owners and reviewers widely praise its attractive design, compelling dimensions, and robust movement. The watch features sharp case lines with contrasting brushing and polishing, a 40mm steel case that provides presence without bulk, and 100m water resistance. Its sunburst blue dial, inspired by the dawn sky over Mount Iwate, showcases Grand Seiko's signature finishing on applied markers and hands, with a red-tipped seconds hand. The 9S65 automatic movement is noted for its precision, running within specifications, with one source reporting a +5 to -3 seconds a day rate and a 3-day power reserve. A blue rotor with a crimson rim, also inspired by Mount Iwate, is visible through the display caseback. On balance, owners and reviewers rate the Grand Seiko SBGR321 highly for its exceptional finishing and compelling blue dial design at its price point.

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