Side by side

Bremont Supermarine 300MvsSeiko King Seiko KSK

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

Supermarine 300M
BremontSupermarine 300M
MSRP $3,550
King Seiko KSK
SeikoKing Seiko KSK
MSRP $3,300

At a glance

14 of 29 specs differ
Diameter
Supermarine 300M40mm
King Seiko KSK38.6mm
Power Reserve
Supermarine 300M40h
King Seiko KSK45h
Water Resistance
Supermarine 300M300m
King Seiko KSK50m
MSRP
Supermarine 300M$3,550
King Seiko KSK$3,300

Full specifications

Case

7 specs
Category
Diver
Dress
Diameter
40mm
38.6mm
Thickness
12mm
10.7mm
Lug-to-Lug
45.8mm
Lug Width
20mm
19mm
Material
904L Stainless Steel
Stainless Steel
Water Resistance
300m
50m

Crystal & Dial

3 specs
Crystal Shape
Flat
Box
AR Coating
Inner
Anti-reflective coating on inner surface
Dial Color
Green
Black

Movement

3 specs
Caliber
BE-92AE
6L35
Power Reserve
40h
45h
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 King Seiko KSK

Owners and reviewers widely praise the King Seiko KSK for its exceptional dial and case finishing, often compared to higher-end brands, and its slim, retro design. The use of the Calibre 6L35 movement in some variants is seen as a significant upgrade, contributing to a refined feel, while others note the bracelet is unusually nice and the case offers a mix of brushed and polished finishes with sharp angles. However, some owners question the value proposition, citing misaligned screws and clasp components on their examples, and the standard 6R movement in some models is criticized as a disappointment for the price point. Accuracy figures range from +15/-10 seconds per day to +5 to +7 seconds per day, and water resistance is rated at 5 BAR or 50 meters. Overall, owners and reviewers find the King Seiko KSK to be a beautiful and classy watch with fantastic finishing, though some are divided on its value and movement choice at its price point.

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