Side by side

Serica Ref. 5303 Diving ChronometervsSeiko Prospex Sea

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

Ref. 5303 Diving Chronometer
SericaRef. 5303 Diving Chronometer
MSRP $1,768
Prospex Sea
SeikoProspex Sea

At a glance

11 of 29 specs differ
Diameter
Ref. 5303 Diving Chronometer39mm
Prospex Sea42mm
Power Reserve
Ref. 5303 Diving Chronometer42h
Prospex Sea72h
Water Resistance
Ref. 5303 Diving Chronometer300m
Prospex Sea300m
MSRP
Ref. 5303 Diving Chronometer$1,768
Prospex Sea

Full specifications

Case

3 specs
Diameter
39mm
42mm
Thickness
12.2mm
13.3mm
Lug-to-Lug
46.5mm
48.6mm

Crystal & Dial

3 specs
AR Coating
Yes
Anti-reflective coating on inner surface
Dial Color
Enamel Black
Black
Lume
Super-LumiNova
LumiBrite on hands, index(es) and bezel

Movement

4 specs
Caliber
M100 COSC
6R54
Power Reserve
42h
72h
Jewels
25
24
Complications
COSC
None

Pricing

1 specs
MSRP
$1,768

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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.

Serica Ref. 5303 Diving Chronometer

Owners widely praise the Serica Ref. 5303 Diving Chronometer for its excellent wearability, definitive style, and smooth, confident bezel action. The dual scale on the bezel is noted as surprisingly useful, and the crown action, winding, and hacking are reported to work perfectly. One owner describes the Serica 5303-3 as gorgeous and unique, though another notes the crown can appear comically large. On balance, owners rate the Serica Ref. 5303 Diving Chronometer highly for its blend of unique design and robust functionality.

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.

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