Side by side

Serica Ref. 5303 Diving ChronometervsSeiko Prospex SPEEDTIMER Seiko 145th Anniversary Limited Edition

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

At a glance

14 of 29 specs differ
Diameter
Ref. 5303 Diving Chronometer39mm
Prospex SPEEDTIMER Seiko 145th Anniversary Limited Edition42mm
Power Reserve
Ref. 5303 Diving Chronometer42h
Prospex SPEEDTIMER Seiko 145th Anniversary Limited Edition45h
Water Resistance
Ref. 5303 Diving Chronometer300m
Prospex SPEEDTIMER Seiko 145th Anniversary Limited Edition100m
MSRP
Ref. 5303 Diving Chronometer$1,768
Prospex SPEEDTIMER Seiko 145th Anniversary Limited Edition$2,500

Full specifications

Case

5 specs
Category
Diver
Chronograph
Diameter
39mm
42mm
Thickness
12.2mm
14.6mm
Lug-to-Lug
46.5mm
49.5mm
Water Resistance
300m
100m

Crystal & Dial

4 specs
Crystal Shape
Flat
Curved
AR Coating
Yes
Anti-reflective coating on inner surface
Dial Color
Enamel Black
Black
Lume
Super-LumiNova
LumiBrite on hands and index(es)

Movement

4 specs
Caliber
M100 COSC
8R48
Power Reserve
42h
45h
Jewels
25
34
Complications
COSC
None

Pricing

1 specs
MSRP
$1,768
$2,500

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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 SPEEDTIMER Seiko 145th Anniversary Limited Edition

Owners widely praise the Prospex SPEEDTIMER Seiko 145th Anniversary Limited Edition for its refined presence and intricate dial patterns, with some favoring its unique red dial and steel bezel over other Speedtimer models. However, some owners criticize the 24-hour subdial as useless, the date window as recessed, and the stock bracelet as difficult to fit, while others find the pushers stick out too much. One owner notes the $995 price point is high for the 6R55 movement, suggesting a lower range, though others appreciate the Seiko finishing and charm. On balance, owners rate the Prospex SPEEDTIMER Seiko 145th Anniversary Limited Edition well for its unique aesthetic and finishing, despite some functional and value concerns.

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