Which is cheaper, the Sinn 103 St Ty Hd or the Seiko Prospex Sea?

At MSRP the Seiko Prospex Sea is the cheaper of the two at $900, against $2,797 for the Sinn 103 St Ty Hd — a $1,897 gap before any retailer discounting.

Which has a longer power reserve, the Sinn 103 St Ty Hd or the Seiko Prospex Sea?

The Seiko Prospex Sea carries a 70-hour power reserve against 48 hours on the Sinn 103 St Ty Hd.

What movement does the Sinn 103 St Ty Hd run compared to the Seiko Prospex Sea?

Both watches run automatic movements — the Sinn 103 St Ty Hd uses the ETA 7750 and the Seiko Prospex Sea uses the 6R35.

Side by side

Sinn 103 St Ty HdvsSeiko Prospex Sea

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

Sinn 103 St Ty Hd

103 St Ty Hd

MSRP $2,797

Seiko Prospex Sea

spb317j1

MSRP $900

At a glance

13 of 29 specs differ

Diameter

103 St Ty Hd41mm

Prospex Sea41mm

Power Reserve

103 St Ty Hd48h

Prospex Sea70h

Water Resistance

103 St Ty Hd200m

Prospex Sea200m

MSRP

103 St Ty Hd$2,797

Prospex Sea$900

Full specifications

Case

5 specs

Crystal & Dial

4 specs

Crystal Shape

—

Curved

AR Coating

—

Anti-reflective coating on inner surface

Indices

—

Applied

Lume

None

LumiBrite on hands, index(es) and bezel

Movement

3 specs

Caliber

ETA 7750

6R35

Power Reserve

48h

70h

Jewels

Pricing

1 specs

MSRP

$2,797

$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 103 St Ty Hd

The Sinn 103 St Ty Hd is widely praised as a stunning, heritage-inspired pilot's chronograph with a utilitarian feel and bold red accents on a black dial. Owners note it offers a different experience compared to typical Sinn watches. It features a hand-wound Sellita SW510 M movement, a 58-hour power reserve, 20 ATM water resistance, and impact-resistant acrylic glass. The Sinn 103 St Ty Hd is priced at €2,590 and is limited to 1,000 units. On balance, owners and reviewers rate the Sinn 103 St Ty Hd highly for its unique aesthetic and tool watch attributes.

From video reviewers

The watch's robustness and ability to withstand extreme conditions without compromising accuracy are notable strengths. The relatively high price point is a shared weakness. Reviewers disagree on the watch's thickness, with one reviewer considering it a drawback and the other not mentioning it.

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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