Side by side

Formex Reef 42 mmvsSeiko Prospex Sea

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

Reef 42 mm
FormexReef 42 mm
MSRP $2,414
Prospex Sea
SeikoProspex Sea
MSRP $1,100
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 42 mm

The Formex Reef 42 mm is widely praised for its comfortable bracelet featuring a micro-adjust clasp, COSC-certified Sellita movement, and excellent build quality. Owners appreciate the gradient dial's visual appeal and the overall wearability. Some owners note the seconds hand does not perfectly align with markers, and one owner found the lugs' taper hinders third-party strap fit. The bracelet's length and sporty design are noted as limiting versatility by some. On balance, owners and reviewers rate the Formex Reef 42 mm highly for its impressive wearability and value at the price point.

Seiko Prospex Sea

Seiko Prospex Sea models are widely praised for their excellent build quality, value for money, and comfortable wearability, with many appreciating the vintage-inspired designs and robust construction. Owners note the silicone straps are surprisingly comfortable and well-finished, and the Lumibrite lume is excellent. However, some find the 44.3mm size and thickness too large for smaller wrists, though others report the sizing as perfect. The 6R15 movement in some variants offers accuracy around +4 seconds per day with a 50-hour power reserve, while newer movements offer more. Some models are criticized for a bracelet width not matching the case size or a rudimentary clasp for their price point. Overall, owners and reviewers rate the Seiko Prospex Sea highly for its impressive case work and finishing at its price point.

At a glance

10 of 29 specs differ
Diameter
Reef 42 mm42mm
Prospex Sea41.3mm
Power Reserve
Reef 42 mm56h
Prospex Sea72h
Water Resistance
Reef 42 mm300m
Prospex Sea300m
MSRP
Reef 42 mm$2,414
Prospex Sea$1,100

Full specifications

Case

4 specs
Diameter
42mm
41.3mm
Thickness
11.4mm
12.5mm
Lug-to-Lug
47mm
48.2mm
Lug Width
22mm
20mm

Crystal & Dial

2 specs
AR Coating
Inner
Anti-reflective coating on inner surface
Lume
Super-LumiNova
LumiBrite on hands, index(es) and bezel

Movement

3 specs
Caliber
Sellita SW300-1
6R55
Power Reserve
56h
72h
Jewels
25
24

Pricing

1 specs
MSRP
$2,414
$1,100
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