Side by side

Bremont Supermarine 300MvsSeiko Prospex Sea 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 Save the Ocean Special Edition45mm
Power Reserve
Supermarine 300M40h
Prospex Sea Save the Ocean Special Edition41h
Water Resistance
Supermarine 300M300m
Prospex Sea Save the Ocean Special Edition200m
MSRP
Supermarine 300M$3,550
Prospex Sea Save the Ocean Special Edition$625

Full specifications

Case

6 specs
Diameter
40mm
45mm
Thickness
12mm
13.2mm
Lug-to-Lug
47.7mm
Lug Width
20mm
22mm
Material
904L Stainless Steel
Stainless Steel
Water Resistance
300m
200m

Crystal & Dial

3 specs
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
4R36
Power Reserve
40h
41h
Jewels
25
24

Pricing

1 specs
MSRP
$3,550
$625

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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 Save the Ocean Special Edition

The Seiko Prospex Sea Save the Ocean Special Edition is widely praised for its attractive, unique, and textured dials, often described as having a "Grand Seiko feel" at a more accessible price point, with specific mentions of wave patterns, lagoon hues, and manta ray motifs. Owners appreciate the smooth bezel operation and satisfactory lume. Accuracy figures vary, with one owner reporting +5 seconds per day, while another notes a range from +1/+2 to about -6 seconds per day. The 6R35 movement offers a 70-hour power reserve, and some models feature sapphire crystals. Criticisms include a desire for exhibition casebacks and concerns about the quality and security of the stamped metal clasps and bracelets, which are frequently described as rattly or underwhelming, though this is noted as a common Seiko trait. Some owners are split on the number of Save the Ocean variations and dislike the cyclops magnifier.

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