Side by side

Formex Reef 39.5 mmvsSeiko Ice Diver

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

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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.

Seiko Ice Diver

Owners widely praise the Seiko Prospex Sea for its robust build, classic dive watch design, and excellent value, with many highlighting its strong lume and comfortable wearability. Reviewers consistently flag its superior bezel action and overall finishing as standout features for its price point. Some owners find the 43mm case size substantial, with one noting it felt big, thick, and heavy on a 6.5-inch wrist, though others consider it a perfect size. The movement's power reserve is noted as less than newer variants by one reviewer. Overall, owners and reviewers rate the Seiko Prospex Sea highly for its classic design and robust build at an accessible price.

At a glance

12 of 29 specs differ
Diameter
Reef 39.5 mm39.5mm
Ice Diver45mm
Power Reserve
Reef 39.5 mm56h
Ice Diver70h
Water Resistance
Reef 39.5 mm300m
Ice Diver200m
MSRP
Reef 39.5 mm$2,230
Ice Diver$900

Full specifications

Case

6 specs
Diameter
39.5mm
45mm
Thickness
11mm
12.9mm
Lug-to-Lug
45.5mm
52.6mm
Lug Width
22mm
20mm
Material
Stainless Steel
Water Resistance
300m
200m

Crystal & Dial

2 specs
Dial Color
Bahama Blue
Lume
Super-LumiNova
LumiBrite

Movement

3 specs
Caliber
Sellita SW300-1
Seiko 6R35
Power Reserve
56h
70h
Jewels
0
24

Pricing

1 specs
MSRP
$2,230
$900
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