Watch Almanac
Christopher Ward

C63 Sealander GMT 39mm

Ref. C63-39AGM4-S00B0-B0

Case diameter
39 mm
Manufacturer spec
Lug-to-lug
45 mm
Manufacturer spec
Thickness
11.3 mm
Manufacturer spec
Lug width
20 mm
Manufacturer spec

Retail price $1,620 (US, Oct 2026)

Ideal fit
Wrist flat: 55.1 mmLug-to-lug: 45 mm

How the C63 Sealander GMT 39mm wears

Its lugs add 6 mm to the 39 mm case, close to the 7.1 mm typical across the almanac, so its diameter is a fair guide to how it wears.

On our fit model it sits best on wrists from 6.25" to 7.5" (15.9–19.1 cm); below 6.25" the lugs start to reach the edge of the wrist.

At 11.3 mm thick it is slimmer than 83% of the 24 other gmt watches we've measured, so it slides under a cuff more easily than most.

Its 20 mm lug width is one of the most common strap sizes; 104 other watches here share it, so aftermarket straps are easy to find.

Will the C63 Sealander GMT 39mm fit your wrist?

With a 45 mm lug-to-lug, here is how it wears across common wrist sizes. We estimate the flat top of each wrist from its circumference; measure yours for a closer answer in the fit finder.

WristFlat width (est.)Fit
6"47.2 mmSnug, lugs near the edge
6.5"51.2 mmIdeal fit
7"55.1 mmIdeal fit
7.5"59.1 mmIdeal fit
8"63 mmWears small

Specifications

Reference
C63-39AGM4-S00B0-B0
Collection
C63 Sealander
Status
In production
Case material
stainless steel
Crystal
sapphire
Water resistance
150 m
Bezel
fixed, steel 24-hour
Dial
sky blue
Strap / bracelet
Bader steel bracelet
Weight
151 g
Style
GMT, Everyday

Movement

Caliber
Sellita Sellita SW330-2
Type
automatic
Power reserve
56 hours
Frequency
28,800 vph (4 Hz)
Jewels
25

3 other watches use the Sellita SW330-2

Takes 20 mm straps. See other 20 mm watches and straps.

More C63 Sealander references

Watches that wear the same size

Other watches within 1.5 mm of its lug-to-lug.

Same 20 mm lug width

All 20 mm watches

These take the same straps as the C63 Sealander GMT 39mm.

Sources