Side by side

Bremont Supermarine 300MvsSeiko King Turtle

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

Supermarine 300M
BremontSupermarine 300M
MSRP $3,550
King Turtle
SeikoKing Turtle
MSRP $650

At a glance

13 of 29 specs differ
Diameter
Supermarine 300M40mm
King Turtle45mm
Power Reserve
Supermarine 300M40h
King Turtle41h
Water Resistance
Supermarine 300M300m
King Turtle200m
MSRP
Supermarine 300M$3,550
King Turtle$650

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 and index(es)

Movement

3 specs
Caliber
BE-92AE
4R36
Power Reserve
40h
41h
Jewels
25
24

Pricing

1 specs
MSRP
$3,550
$650

Follow this matchup

Get a note when Bremont Supermarine 300M vs Seiko King Turtle gets more votes, a community discussion, or a price drop. No account needed.

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 Turtle

Owners widely praise the Seiko Prospex Sea for its excellent value, robust build, and superior lume, with many appreciating its faithful recreation of classic designs and proven movements like the 4R36 and 6R15. Reviewers highlight impressive case finishing and durability, noting that even larger models wear smaller than expected due to thoughtful case design. Some owners find the solar quartz models a great entry point, appreciating their design and solar functionality. However, specific variants receive critiques: the bracelet clasp on the Samurai is described as underwhelming, and the Sumo's bracelet width and clasp are seen as too narrow and rudimentary, respectively. The SPB183 is considered expensive for a Japanese watch, and its lume is noted as not quite matching older Seiko Monster models. The GMT function on the SPB519 is deemed less practical for serious travel, and its bezel clicks are described as quieter and mushier.

Keep exploring

More watches worth a look

Matched to the watches above on size, movement, style and price — microbrands first. Open any one to dig in.

Adjacent matchups

People also compared

Comparisons nearby in the catalog — alternatives to the watches above paired against the matchup.