Seiko Prospex Sea 1968 Heritage Diver's GMT Limited EditionvsSynchron Poseidon

lug2lug doesn't sell watches. Buy links open the brand's or seller's own site. Some links are affiliate links: lug2lug may earn a commission at no extra cost to you. Disclosures

Measurements

Catalog photos are all shot at the same flattering size. These aren't: every case below shares one millimeter scale.

Seiko Prospex Sea 1968 Heritage Diver's GMT Limited Edition at true scale

Prospex Sea 1968 Heritage Diver's GMT Limited Edition

Synchron Poseidon at true scale

Poseidon

Diameter

42mm

41mm

Lug-to-Lug

48.6mm

45mm

lowest

Thickness

13.3mm

11.9mm

lowest

Water Resistance

300m

300m

Power Reserve

72h

highest

68h

MSRP

$1,750

n/a

Movement

Seiko 6R54

La Joux-Perret G100

Case

4 specs
Diameter
42mm
41mm
Thickness
13.3mm
11.9mm
Lug-to-Lug
48.6mm
45mm
Material
Stainless Steel
Titanium

Crystal & Dial

3 specs
AR Coating
Anti-reflective coating on inner surface
n/a
Dial Color
n/a
Sunshine Yellow
Lume
LumiBrite on hands, index(es) and bezel
None

Movement

3 specs
Caliber
Seiko 6R54
La Joux-Perret G100
Power Reserve
72h
68h
Jewels
24
0

Pricing

1 specs
MSRP
$1,750
n/a
Keep your wishlist and collection together in the appExplore the app

Reviews

Synthesized for each watch independently from owner discussions, enthusiast forums, written reviews, and video reviewers.

Seiko Prospex Sea 1968 Heritage Diver's GMT Limited Edition

The Seiko Prospex Sea 1968 Heritage Diver's GMT Watch Limited Edition is widely praised for its excellent quality and finishing for its price, with reviewers highlighting its beautiful case, bracelet, and Lumibrite lume. Owners appreciate the comfortable 42mm case size and the 4 o'clock crown position. The watch features a sapphire crystal and uses the in-house 6R54 automatic movement with a three-day power reserve. Some reviewers note that the GMT function is secondary and that the bezel clicks are quieter than expected. The 4:30 date window splits opinion among enthusiasts, and it is described as a "caller GMT" rather than a true "traveller GMT." Overall, owners and reviewers rate the Seiko Prospex Sea 1968 Heritage Diver's GMT Watch Limited Edition highly for its excellent value, quality finishing, and comfortable wearability.

Synchron Poseidon

Owners widely praise the Synchron Poseidon for its vintage-inspired diver aesthetics, easy-to-read dial, and precise, grippy bezel. The La Joux-Perret G100 movement is consistently noted as a strong point, with owners reporting good timekeeping, one seeing accuracy around -4 seconds per day, and others highlighting its 68-hour power reserve. The winding action and crown operation are described as reassuring, with one reviewer stating it surpasses watches at double the price. Some find the design busy or the branding confusing, and the blasted finish on the steel bezel rim contrasts with the brushed case. One owner noted the included Isofrane strap can be long for smaller wrists. On balance, owners and reviewers rate the Synchron Poseidon highly for its robust build, reliable movement, and excellent value.

Similar watches

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

DiscussionNot started

Also compared

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