Side by side

Seiko Prospex SeavsSinn U1 S L

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

The Seiko Prospex Sea is widely praised for its excellent value, solid build quality, and comfortable wearability, with many models featuring impressive lume and attractive dials. Owners and reviewers highlight the modern upgrades on classic designs, such as drilled lugs and reliable movements with hacking and hand-winding capabilities. Some models are noted for their refined case finishing and scratch resistance. Accuracy figures vary, with one owner reporting approximately 4 seconds fast per day, while others find the movements offer good performance for the price. Concerns raised by owners and reviewers include clasps that can feel generic or cheap, and lug widths that some find disproportionate to the case size on certain models. The thickness and weight of some Prospex Sea watches are also noted as substantial. The GMT function on specific models is considered secondary and difficult to read for true travel purposes.

Sinn U1 S L

The Sinn U1 S L is widely praised for its intense, full-lume dial, a feature described as new technology that glows brightly, and its unique black and white "arctic tactical" aesthetic. Owners and reviewers consistently highlight the Tegimented German submarine steel case for its exceptional scratch resistance and matte, non-reflective finish, with one owner reporting no scratches on the case after 17 years. The watch is also noted for its legibility and robust build, offering 1000m water resistance. However, some owners find the 44mm size and 14.7mm thickness wear large, and one reviewer noted the 4 o'clock crown positions lacked distinct clicks, leading to difficult date changes. Accuracy figures for the ETA 2824-2 movement vary, with one owner seeing +1/+2 s/day and another about -6 s/day. The Tegimented bracelet is reported to scratch more easily than the case by some, while others found it held up well.

At a glance

16 of 29 specs differ
Diameter
Prospex Sea43.8mm
U1 S L44mm
Power Reserve
Prospex Sea41h
U1 S L38h
Water Resistance
Prospex Sea200m
U1 S L1,000m
MSRP
Prospex Sea$625
U1 S L$3,532

Full specifications

Case

6 specs
Diameter
43.8mm
44mm
Thickness
12.8mm
14.7mm
Lug-to-Lug
48.7mm
Finish
black
Water Resistance
200m
1000m
Caseback

Crystal & Dial

5 specs
Crystal Shape
AR Coating
Anti-reflective coating on inner surface
Underside
Dial Color
Black
Indices
Lume
LumiBrite on hands, index(es) and bezel
Luminescent

Movement

4 specs
Caliber
Seiko 4R35
Sellita SW200-1
Beat Rate
0 vph
28,800 vph
Power Reserve
41h
38h
Jewels
23
26

Pricing

1 specs
MSRP
$625
$3,532
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