Side by side

Seestern S450 Ocean StarvsZelos Helica Moonphase

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

S450 Ocean Star
SeesternS450 Ocean Star
MSRP $299
Helica Moonphase
ZelosHelica Moonphase
MSRP $1,049

At a glance

12 of 29 specs differ
Diameter
S450 Ocean Star40mm
Helica Moonphase39mm
Power Reserve
S450 Ocean Star41h
Helica Moonphase40h
Water Resistance
S450 Ocean Star100m
Helica Moonphase100m
MSRP
S450 Ocean Star$299
Helica Moonphase$1,049

Full specifications

Case

4 specs
Category
Diver
Moonphase
Diameter
40mm
39mm
Thickness
12mm
10mm
Lug-to-Lug
48mm
39mm

Crystal & Dial

2 specs
Dial Color
White
Meteorite
Lume
Tritium
None

Movement

5 specs
Caliber
TMI NH35A
Sellita SW288 Moonphase
Beat Rate
21,600 vph
28,800 vph
Power Reserve
41h
40h
Jewels
24
25
Complications
GMT, Date
None

Pricing

1 specs
MSRP
$299
$1,049

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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.

Zelos Helica Moonphase

Owners widely praise the Zelos Helica Moonphase for its gorgeous aventurine dial, unique industrial-dress aesthetic, and comfortable wearability, with one owner calling it spectacular and another their favorite Zelos. The moonphase complication is frequently highlighted as beautiful, though some find the double moon distracting or the dial cluttered. A manual-wind movement combined with a screw-down crown is noted as a drawback by some, requiring adjustment and potentially feeling fragile when fully wound, while one owner reports a 43-hour power reserve. On balance, owners rate the Zelos Helica Moonphase highly for its stunning aventurine dial and unique design at its price point.

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