Side by side

Bremont Supermarine 300MvsSeiko Prospex Sea 1970 Heritage Diver's Black Series Limited 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 Black Series Limited Edition44mm
Power Reserve
Supermarine 300M40h
Prospex Sea 1970 Heritage Diver's Black Series Limited Edition50h
Water Resistance
Supermarine 300M300m
Prospex Sea 1970 Heritage Diver's Black Series Limited Edition200m
MSRP
Supermarine 300M$3,550
Prospex Sea 1970 Heritage Diver's Black Series Limited Edition$3,300

Full specifications

Case

5 specs
Diameter
40mm
44mm
Thickness
12mm
13mm
Lug-to-Lug
49.3mm
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
8L35
Power Reserve
40h
50h
Jewels
25
26

Pricing

1 specs
MSRP
$3,550
$3,300

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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 Black Series Limited Edition

Owners widely praise the Seiko Prospex Sea 1970 Heritage Diver's Black Series Limited Edition for its attractive, well-made design and gorgeous dial, noting its jewel-toned teal color and rippling-water pattern. The bezel action is smooth with a muted sound, and the case and bracelet offer a more comfortable feel than previous iterations. However, multiple owners express disappointment with the accuracy of the 6R movement at its price point, with some noting theirs runs slow, and consider the price too high. The steep rehaut and marker size make the 24-hour numbers difficult to read, and some find the case design makes the watch feel top-heavy despite wearing smaller. Overall, owners rate the Seiko Prospex Sea 1970 Heritage Diver's Black Series Limited Edition highly for its striking dial and refined case design, despite concerns regarding movement accuracy at its price.

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