Side by side

Formex Reef 42 mmvsSeiko Prospex Sea 1970 Heritage Diver's Save the Ocean Special Edition

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

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 1970 Heritage Diver's Save the Ocean Special Edition

The Seiko Prospex Sea 1970 Heritage Diver's Save the Ocean Special Edition is praised for its beautiful design and refinement over previous models, featuring vertically textured glacier-inspired dials. Owners, however, consider the €1500 RRP too high, suggesting a price closer to €900-€1000, noting the aluminum bezel insert instead of ceramic. Some owners report the 6R movement runs slow. On balance, owners find the Seiko Prospex Sea 1970 Heritage Diver's Save the Ocean Special Edition beautiful and a refinement, but the price and aluminum bezel are points of contention.

At a glance

13 of 29 specs differ
Diameter
Reef 42 mm42mm
Prospex Sea 1970 Heritage Diver's Save the Ocean Special Edition42.7mm
Power Reserve
Reef 42 mm56h
Prospex Sea 1970 Heritage Diver's Save the Ocean Special Edition70h
Water Resistance
Reef 42 mm300m
Prospex Sea 1970 Heritage Diver's Save the Ocean Special Edition200m
MSRP
Reef 42 mm$2,414
Prospex Sea 1970 Heritage Diver's Save the Ocean Special Edition$1,350

Full specifications

Case

5 specs
Diameter
42mm
42.7mm
Thickness
11.4mm
13.2mm
Lug-to-Lug
47mm
46.4mm
Lug Width
22mm
20mm
Water Resistance
300m
200m

Crystal & Dial

4 specs
Crystal Shape
Curved
AR Coating
Anti-reflective coating on inner surface
Dial Color
Black
Lume
Super-LumiNova
LumiBrite on hands, index(es) and bezel

Movement

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

Pricing

1 specs
MSRP
$2,414
$1,350
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