Side by side

Sinn 105 St Sa UTCvsSeiko Prospex Sea

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

105 St Sa UTC
Sinn105 St Sa UTC
MSRP $1,998
Prospex Sea
SeikoProspex Sea
MSRP $900

At a glance

14 of 29 specs differ
Diameter
105 St Sa UTC41mm
Prospex Sea41mm
Power Reserve
105 St Sa UTC38h
Prospex Sea70h
Water Resistance
105 St Sa UTC200m
Prospex Sea200m
MSRP
105 St Sa UTC$1,998
Prospex Sea$900

Full specifications

Case

5 specs
Category
Tool
Diver
Thickness
11.9mm
12.3mm
Lug-to-Lug
46.9mm
Finish
bead-blasted
Brushed and polished
Caseback
Solid

Crystal & Dial

4 specs
Crystal Shape
Curved
AR Coating
Underside
Anti-reflective coating on inner surface
Indices
Applied
Lume
Luminescent
LumiBrite on hands, index(es) and bezel

Movement

4 specs
Caliber
SW 330-2
6R35
Power Reserve
38h
70h
Jewels
25
24
Complications
Date, GMT
None

Pricing

1 specs
MSRP
$1,998
$900

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What people say

Owners + reviewers, side by side

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

Sinn 105 St Sa UTC

Owners and reviewers widely praise the Sinn 105 St Sa UTC for its legible dial, precise bi-directional bezel action, and the technical, toolish aesthetic of its bead-blasted, TEGIMENT-hardened steel case. The watch is noted for its smooth sweep and snappy date change, with accuracy often within COSC standards, and its vertical day/date display with a German day wheel is a distinctive feature. Some owners find the lug-to-lug distance large for smaller wrists, and the bracelet clasp is considered a weakness by one source, while the non-lumed UTC hand is a deliberate design choice. The Sinn 105 St Sa UTC utilizes a Sellita SW330-1 automatic movement with a 42-hour power reserve and offers 200 meters of water resistance. Overall, the consensus is that owners and reviewers rate the Sinn 105 St Sa UTC highly for its robust build quality and functional tool watch design at its price point.

Seiko Prospex Sea

Owners widely praise the Seiko Prospex Sea for its excellent lume, robust build, and value, with many highlighting the comfortable 4 o'clock crown and reliable movements. Reviewers note impressive case finishing and attractive dials, with specific models lauded for their gradient blue designs and smooth bezel actions. Accuracy figures vary, with one owner reporting +9 seconds/day after demagnetization, while others find the watches to be good first "proper" watches. Some owners find the stock rubber straps uncomfortable or the overall size substantial on smaller wrists. On balance, owners and reviewers rate the Seiko Prospex Sea highly for its combination of strong dive watch functionality and appealing design at its price point.

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