Side by side

Serica Ref. 5303 Diving ChronometervsFormex Reef 42 mm

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
Reef 42 mm
FormexReef 42 mm
MSRP $2,414

At a glance

10 of 29 specs differ
Diameter
Ref. 5303 Diving Chronometer39mm
Reef 42 mm42mm
Power Reserve
Ref. 5303 Diving Chronometer42h
Reef 42 mm56h
Water Resistance
Ref. 5303 Diving Chronometer300m
Reef 42 mm300m
MSRP
Ref. 5303 Diving Chronometer$1,768
Reef 42 mm$2,414

Full specifications

Case

4 specs
Diameter
39mm
42mm
Thickness
12.2mm
11.4mm
Lug-to-Lug
46.5mm
47mm
Lug Width
20mm
22mm

Crystal & Dial

2 specs
AR Coating
Yes
Inner
Dial Color
Enamel Black
Black

Movement

3 specs
Caliber
M100 COSC
Sellita SW300-1
Power Reserve
42h
56h
Complications
COSC
None

Pricing

1 specs
MSRP
$1,768
$2,414

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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.

Formex Reef 42 mm

The Formex Reef 42 mm is widely praised for its comfortable bracelet featuring a micro-adjust clasp, COSC-certified Sellita movement, and excellent build quality. Owners appreciate the gradient dial's visual appeal and the overall wearability. Some owners note the seconds hand does not perfectly align with markers, and one owner found the lugs' taper hinders third-party strap fit. The bracelet's length and sporty design are noted as limiting versatility by some. On balance, owners and reviewers rate the Formex Reef 42 mm highly for its impressive wearability and value at the price point.

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