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Seiko Prospex Sea Save the Ocean Special EditionvsSinn U18

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

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 Save the Ocean Special Edition

Owners widely praise the Seiko Prospex Sea Save the Ocean Special Edition for its exceptional and captivating dial designs, often described as a highlight that evokes ocean surfaces with unique textures and color gradients. The watch is frequently noted for its excellent value, with some reviewers comparing its aesthetics to much higher-priced brands. Owners report satisfactory lume and accurate timekeeping, with figures ranging from +5 seconds per day to more precise results. However, some owners and reviewers point to the bracelet clasp as a point of criticism, describing it as underwhelming or flimsy, and some find the watch to be top-heavy. There are also mentions of imperfect day/date wheel alignment and occasional bezel alignment issues on some models within the line. The Seiko Prospex Sea Save the Ocean Special Edition is available in various case sizes, with some owners questioning if certain dimensions are too bulky for daily wear.

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

17 of 29 specs differ
Diameter
Prospex Sea Save the Ocean Special Edition43.8mm
U1844mm
Power Reserve
Prospex Sea Save the Ocean Special Edition41h
U1842h
Water Resistance
Prospex Sea Save the Ocean Special Edition200m
U182,000m
MSRP
Prospex Sea Save the Ocean Special Edition$650
U18$3,488

Full specifications

Case

7 specs
Diameter
43.8mm
44mm
Thickness
12.8mm
15.5mm
Lug-to-Lug
48.7mm
Material
Stainless Steel
high-strength
Finish
Water Resistance
200m
2000m
Caseback

Crystal & Dial

5 specs
Crystal Shape
AR Coating
Anti-reflective coating on inner surface
Dial Color
Black
Indices
Lume
LumiBrite on hands, index(es) and bezel
None

Movement

4 specs
Caliber
4R35
Sellita SW300-1
Beat Rate
0 vph
28,800 vph
Power Reserve
41h
42h
Jewels
23
25

Pricing

1 specs
MSRP
$650
$3,488
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