Side by side

Serica Ref. 5303 Diving ChronometervsSeiko 5KX

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
5KX
Seiko5KX
MSRP $350

At a glance

14 of 29 specs differ
Diameter
Ref. 5303 Diving Chronometer39mm
5KX42.5mm
Power Reserve
Ref. 5303 Diving Chronometer42h
5KX41h
Water Resistance
Ref. 5303 Diving Chronometer300m
5KX100m
MSRP
Ref. 5303 Diving Chronometer$1,768
5KX$350

Full specifications

Case

5 specs
Diameter
39mm
42.5mm
Thickness
12.2mm
13.4mm
Lug-to-Lug
46.5mm
46mm
Lug Width
20mm
22mm
Water Resistance
300m
100m

Crystal & Dial

4 specs
Crystal
Sapphire
Hardlex
AR Coating
Yes
Inner
Dial Color
Enamel Black
Black
Lume
Super-LumiNova
LumiBrite on hands and index(es)

Movement

4 specs
Caliber
M100 COSC
4R36
Power Reserve
42h
41h
Jewels
25
24
Complications
COSC
None

Pricing

1 specs
MSRP
$1,768
$350

Follow this matchup

Get a note when Serica Ref. 5303 Diving Chronometer vs Seiko 5KX 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.

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 5KX

Owners widely praise the Seiko 5 Sports SKX series for its strong lume and comfortable wearability, with many noting its compact feel due to a short lug-to-lug length. The NH36 movement's accuracy varies, with typical performance between +/-5 to 10 seconds per day, though some report better. A lack of screw-down crown and ISO certification are noted drawbacks for its water resistance. Some owners find the bracelet to be of cheaper construction with hollow links, and a few have reported quality control issues. The consensus is that the Seiko 5 Sports SKX series offers good value for its price, appealing to those who appreciate its tool-like nature and iconic lineage.

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.