Side by side

Seestern S450 Ocean StarvsYema Wristmaster Slim CMM.20

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

S450 Ocean Star
SeesternS450 Ocean Star
MSRP $299
Wristmaster Slim CMM.20
YemaWristmaster Slim CMM.20
MSRP $2,117

At a glance

13 of 29 specs differ
Diameter
S450 Ocean Star40mm
Wristmaster Slim CMM.2039mm
Power Reserve
S450 Ocean Star41h
Wristmaster Slim CMM.2040h
Water Resistance
S450 Ocean Star100m
Wristmaster Slim CMM.20100m
MSRP
S450 Ocean Star$299
Wristmaster Slim CMM.20$2,117

Full specifications

Case

5 specs
Category
Diver
GMT
Diameter
40mm
39mm
Thickness
12mm
9mm
Lug-to-Lug
48mm
Lug Width
20mm
24mm

Crystal & Dial

2 specs
Dial Color
White
Black
Lume
Tritium
None

Movement

5 specs
Caliber
TMI NH35A
Yema CMM.20
Beat Rate
21,600 vph
28,800 vph
Power Reserve
41h
40h
Jewels
24
25
Complications
GMT, Date
None

Pricing

1 specs
MSRP
$299
$2,117

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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.

Yema Wristmaster Slim CMM.20

The Yema Wristmaster Slim CMM.20 is widely praised for its compelling integrated bracelet design and comfortable 39mm wearability. Reviewers highlight its impressive value, featuring an in-house CMM.20 micro-rotor movement with a 70-hour power reserve, adjusted to -3/+7 seconds per day, all within a slim 9mm case. Some note the domed sapphire crystal can produce glare and the dial text is quite small. On balance, reviewers rate the Yema Wristmaster Slim CMM.20 highly for its integrated design and value proposition with a micro-rotor movement.

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