Side by side

Seestern S450 Ocean StarvsSeiko Prospex Sea

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

S450 Ocean Star
SeesternS450 Ocean Star
MSRP $299
Prospex Sea
SeikoProspex Sea
MSRP $625

At a glance

14 of 29 specs differ
Diameter
S450 Ocean Star40mm
Prospex Sea43.8mm
Power Reserve
S450 Ocean Star41h
Prospex Sea41h
Water Resistance
S450 Ocean Star100m
Prospex Sea200m
MSRP
S450 Ocean Star$299
Prospex Sea$625

Full specifications

Case

6 specs
Diameter
40mm
43.8mm
Thickness
12mm
12.8mm
Lug-to-Lug
48mm
48.7mm
Lug Width
20mm
22mm
Material
316L Stainless Steel
Stainless Steel
Water Resistance
100m
200m

Crystal & Dial

3 specs
AR Coating
Inner
Anti-reflective coating on inner surface
Dial Color
White
Black
Lume
Tritium
LumiBrite on hands, index(es) and bezel

Movement

4 specs
Caliber
TMI NH35A
4R35
Beat Rate
21,600 vph
28,800 vph
Jewels
24
23
Complications
GMT, Date
None

Pricing

1 specs
MSRP
$299
$625

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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.

Seiko Prospex Sea

The Seiko Prospex Sea is widely praised for its excellent value, solid build quality, and comfortable wearability, with many models featuring impressive lume and attractive dials. Owners and reviewers highlight the modern upgrades on classic designs, such as drilled lugs and reliable movements with hacking and hand-winding capabilities. Some models are noted for their refined case finishing and scratch resistance. Accuracy figures vary, with one owner reporting approximately 4 seconds fast per day, while others find the movements offer good performance for the price. Concerns raised by owners and reviewers include clasps that can feel generic or cheap, and lug widths that some find disproportionate to the case size on certain models. The thickness and weight of some Prospex Sea watches are also noted as substantial. The GMT function on specific models is considered secondary and difficult to read for true travel purposes.

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