Side by side

Formex Reef 39.5 mmvsSeestern S450 Ocean Star

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

Reef 39.5 mm
FormexReef 39.5 mm
MSRP $2,230
S450 Ocean Star
SeesternS450 Ocean Star
MSRP $299

At a glance

14 of 29 specs differ
Diameter
Reef 39.5 mm39.5mm
S450 Ocean Star40mm
Power Reserve
Reef 39.5 mm56h
S450 Ocean Star41h
Water Resistance
Reef 39.5 mm300m
S450 Ocean Star100m
MSRP
Reef 39.5 mm$2,230
S450 Ocean Star$299

Full specifications

Case

6 specs
Diameter
39.5mm
40mm
Thickness
11mm
12mm
Lug-to-Lug
45.5mm
48mm
Lug Width
22mm
20mm
Material
Stainless Steel
316L Stainless Steel
Water Resistance
300m
100m

Crystal & Dial

2 specs
Dial Color
Bahama Blue
White
Lume
Super-LumiNova
Tritium

Movement

5 specs
Caliber
Sellita SW300-1
TMI NH35A
Beat Rate
28,800 vph
21,600 vph
Power Reserve
56h
41h
Jewels
25
24
Complications
None
GMT, Date

Pricing

1 specs
MSRP
$2,230
$299

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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.

Formex Reef 39.5 mm

The Formex Reef 39.5 mm is widely praised for its refined finishing, comfortable and well-proportioned case design, and impressive specifications for its price point, including COSC-certified Sellita SW300-1 movement and 300m water resistance. Owners and reviewers highlight the tool-less micro-adjust clasp and quick-release spring bars as practical features. Some reviewers note that the 22mm lug width feels slightly disproportionate to the smaller case, and the bracelet could benefit from more taper, though this is a point of contention for some owners who value the overall package. A prototype crown protrusion issue is noted as being addressed for production. On balance, owners and reviewers rate the Formex Reef 39.5 mm highly for its excellent value and well-executed design.

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.

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