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Seiko Prospex Sea 1970 Heritage Diver's Black Series Limited EditionvsSinn U18

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

U18
SinnU18
MSRP $3,488
What people say

Owners + reviewers, side by side

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

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.

Sinn U18

The Sinn U18 is praised for its unique deep blue/green dial with three-dimensional oxygen bubbles that change with light, and its comfortable, easily adjustable bracelet. Owners find the watch stunning and a piece of history, appreciating the refined hands. The Sinn U18 features a 44mm, 15.5mm thick case made from German submarine steel, offering a 2000-meter dive specification and Sinn's Ar-Dehumidifying technology, powered by a Sellita SW300-1 movement. The case thickness is apparent, and the watch comes as a complete set with box and papers for $3,000-$3,680. On balance, owners and reviewers rate the Sinn U18 highly for its striking dial and robust build.

At a glance

15 of 29 specs differ
Diameter
Prospex Sea 1970 Heritage Diver's Black Series Limited Edition44mm
U1844mm
Power Reserve
Prospex Sea 1970 Heritage Diver's Black Series Limited Edition50h
U1842h
Water Resistance
Prospex Sea 1970 Heritage Diver's Black Series Limited Edition200m
U182,000m
MSRP
Prospex Sea 1970 Heritage Diver's Black Series Limited Edition$3,300
U18$3,488

Full specifications

Case

7 specs
Thickness
13mm
15.5mm
Lug-to-Lug
49.3mm
Lug Width
20mm
22mm
Material
Stainless Steel
high-strength
Finish
Brushed and polished
Water Resistance
200m
2000m
Caseback
Solid

Crystal & Dial

4 specs
Crystal Shape
Curved
AR Coating
Anti-reflective coating on inner surface
Indices
Applied
Lume
LumiBrite on hands, index(es) and bezel
None

Movement

3 specs
Caliber
8L35
Sellita SW300-1
Power Reserve
50h
42h
Jewels
26
25

Pricing

1 specs
MSRP
$3,300
$3,488
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