Side by side

Serica Ref. 5303 Diving ChronometervsZelos Helica

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
Helica
ZelosHelica
MSRP $499

At a glance

11 of 29 specs differ
Diameter
Ref. 5303 Diving Chronometer39mm
Helica39mm
Power Reserve
Ref. 5303 Diving Chronometer42h
Helica40h
Water Resistance
Ref. 5303 Diving Chronometer300m
Helica100m
MSRP
Ref. 5303 Diving Chronometer$1,768
Helica$499

Full specifications

Case

4 specs
Thickness
12.2mm
10.5mm
Lug-to-Lug
46.5mm
39mm
Material
Stainless Steel
316L Stainless Steel
Water Resistance
300m
100m

Crystal & Dial

3 specs
AR Coating
Yes
Inner
Dial Color
Enamel Black
39 - Wave MOP
Lume
Super-LumiNova
None

Movement

3 specs
Caliber
M100 COSC
Miyota 9015
Power Reserve
42h
40h
Complications
COSC
None

Pricing

1 specs
MSRP
$1,768
$499

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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.

Zelos Helica

Owners widely praise the Zelos Helica for its stunning, often color-shifting dials, with specific mentions of the MoP, slate grey, 'Steel Blue', and red opal variants being particularly captivating and artful. The 39mm case size is noted as fitting well on smaller wrists, and the overall build quality and finishing for the price are frequently highlighted as impressive, with one owner calling it "a lot of watch for the price." Some owners appreciate the novel bracelet designs and full lume dials, while others find the bracelet and clasp edges sharp or the clasp lacking on-the-fly adjustment. Opinions on the date window are mixed, with one owner disliking it. The Zelos Helica Moonphase was considered cluttered by one owner, and its $1K USD price point was felt to be steep by another, though popular variants sold out rapidly. Overall, owners rate the Zelos Helica highly for its striking dial designs and impressive value proposition.

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