Side by side

Sinn 103 St DIAPALvsSeiko Prospex Sea

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

103 St DIAPAL
Sinn103 St DIAPAL
MSRP $4,320
Prospex Sea
SeikoProspex Sea

At a glance

17 of 29 specs differ
Diameter
103 St DIAPAL41mm
Prospex Sea42mm
Power Reserve
103 St DIAPAL48h
Prospex Sea72h
Water Resistance
103 St DIAPAL200m
Prospex Sea300m
MSRP
103 St DIAPAL$4,320
Prospex Sea

Full specifications

Case

7 specs
Category
Tool
Diver
Diameter
41mm
42mm
Thickness
17mm
13.3mm
Lug-to-Lug
48.6mm
Finish
polished
Brushed and polished
Water Resistance
200m
300m
Caseback
Solid

Crystal & Dial

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

Movement

4 specs
Caliber
LJP 8000
6R54
Power Reserve
48h
72h
Jewels
28
24
Complications
GMT, Date, Chronograph, Pilot's Bezel
None

Pricing

1 specs
MSRP
$4,320

Follow this matchup

Get a note when Sinn 103 St DIAPAL vs Seiko Prospex Sea 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.

Sinn 103 St DIAPAL

Owners widely praise the Sinn 103 St DIAPAL for its robust, Germanic design, legible dial, and functional combination of a chronograph and countdown bezel, all offered at a strong value compared to other classic chronographs. The tall, domed acrylic crystal is a favored feature for its warm look and impact resistance, and the polished stainless steel case is preferred by some over a matte finish. The watch meets DIN standards for anti-magnetic, water, and shock resistance, with low-pressure resistance. Some owners note the Sinn 103 St DIAPAL is thick, though its wearability is considered good even on smaller wrists. Availability in the US market without retail distribution is a noted concern for some. Overall, owners rate the Sinn 103 St DIAPAL highly for its rugged tool-watch functionality and distinctive vintage-inspired aesthetic at a competitive price.

Seiko Prospex Sea

Owners widely praise the Seiko Prospex Sea for its excellent value, solid build, and comfortable wearability, with specific mentions of its matte black dial, excellent lume, and cushion case that wears smaller than its dimensions suggest. The 4R36 movement is noted for hacking and hand-winding capabilities, and the bezel action is described as smooth and precise. Some owners find the watch to be a legitimate tool with a fair price, while others describe it as big, thick, and heavy, uncomfortable for smaller wrists, though this is subjective as one owner found the size perfect. The solar quartz movement is also highlighted as a collection-worthy feature. On balance, owners and reviewers rate the Seiko Prospex Sea highly for its exceptional value and comfortable, classic design.

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.