Side by side

Bremont Supermarine 300MvsSeiko 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.

Supermarine 300M
BremontSupermarine 300M
MSRP $3,550

At a glance

13 of 29 specs differ
Diameter
Supermarine 300M40mm
Prospex Sea 1970 Heritage Diver's Save the Ocean Special Edition42.7mm
Power Reserve
Supermarine 300M40h
Prospex Sea 1970 Heritage Diver's Save the Ocean Special Edition70h
Water Resistance
Supermarine 300M300m
Prospex Sea 1970 Heritage Diver's Save the Ocean Special Edition200m
MSRP
Supermarine 300M$3,550
Prospex Sea 1970 Heritage Diver's Save the Ocean Special Edition$1,350

Full specifications

Case

5 specs
Diameter
40mm
42.7mm
Thickness
12mm
13.2mm
Lug-to-Lug
46.4mm
Material
904L Stainless Steel
Stainless Steel
Water Resistance
300m
200m

Crystal & Dial

4 specs
Crystal Shape
Flat
Curved
AR Coating
Inner
Anti-reflective coating on inner surface
Dial Color
Green
Black
Lume
None
LumiBrite on hands, index(es) and bezel

Movement

3 specs
Caliber
BE-92AE
6R35
Power Reserve
40h
70h
Jewels
25
24

Pricing

1 specs
MSRP
$3,550
$1,350

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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.

Bremont Supermarine 300M

The Bremont Supermarine 300M is praised for its comfortable 40mm and 42mm case sizes, with owners noting the 42mm wears well on smaller wrists due to its lug design. One owner highlights the 13mm thinness of the 40mm case, considered compact for a 300m diver. The watch is priced at $1375. On balance, owners and reviewers appreciate the Bremont Supermarine 300M for its wearability and compact dimensions, especially for a dive watch.

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.

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