Side by side

AVI-8 Flyboy Airmaster GMT AutomaticvsSeiko Prospex Marinemaster Marinemaster 1965 Heritage Diver's Watch

The numbers, the dial colors, the calibers — laid out so you can stop flipping between tabs.

Flyboy Airmaster GMT Automatic
AVI-8Flyboy Airmaster GMT Automatic
MSRP $365

At a glance

14 of 29 specs differ
Diameter
Flyboy Airmaster GMT Automatic40mm
Prospex Marinemaster Marinemaster 1965 Heritage Diver's Watch39.5mm
Power Reserve
Flyboy Airmaster GMT Automatic40h
Prospex Marinemaster Marinemaster 1965 Heritage Diver's Watch45h
Water Resistance
Flyboy Airmaster GMT Automatic50m
Prospex Marinemaster Marinemaster 1965 Heritage Diver's Watch200m
MSRP
Flyboy Airmaster GMT Automatic$365
Prospex Marinemaster Marinemaster 1965 Heritage Diver's Watch$2,800

Full specifications

Case

7 specs
Category
GMT
Diver
Diameter
40mm
39.5mm
Thickness
12.3mm
Lug-to-Lug
47.2mm
Lug Width
20mm
Material
316L Stainless Steel
Stainless Steel
Water Resistance
50m
200m

Crystal & Dial

3 specs
Crystal Shape
Flat
Box
AR Coating
Inner
Anti-reflective coating on inner surface
Lume
None
LumiBrite on hands, index(es) and bezel

Movement

3 specs
Caliber
NH34
6L37
Power Reserve
40h
45h
Jewels
25
26

Pricing

1 specs
MSRP
$365
$2,800

Follow this matchup

Get a note when AVI-8 Flyboy Airmaster GMT Automatic vs Seiko Prospex Marinemaster Marinemaster 1965 Heritage Diver's Watch 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.

AVI-8 Flyboy Airmaster GMT Automatic

Owners widely praise the AVI-8 Flyboy Airmaster GMT Automatic for its robust build quality, intricate three-timezone function, and crisp dial texture. The watch is noted for its wearable 41mm case size and 48.5mm lug-to-lug, with an internally positioned GMT complication that maintains a clean dial appearance. Some owners report the stock leather strap feels cheap and limits strap changing options. On balance, owners rate the AVI-8 Flyboy Airmaster GMT Automatic highly for its solid finishing and value, particularly highlighting the dial's depth and texture.

Seiko Prospex Marinemaster Marinemaster 1965 Heritage Diver's Watch

The Seiko Prospex Marinemaster 1965 Heritage Diver's Watch is praised for its faithful re-creation of the 62MAS design, with reviewers noting improved wearability due to smaller case sizes (38mm to 40mm) and updated bracelets. Specific models feature a stainless steel case with super-hard coating, ceramic bezel, and a tool-free extension system on the bracelet. Accuracy figures vary, with one model rated at -5/+10 seconds per day and another at -10/+15 seconds per day, powered by movements like the Caliber 8L45 or 6L37 offering 72-hour or 46-hour power reserves respectively. Some reviewers point out drawbacks such as an unsigned winding crown, a lack of tool-free micro-adjust on the clasp for certain models, and a secondary GMT function on one variant. The price point, ranging from $2,800 to $3,600, is considered high by some, especially when compared to other Seiko or Grand Seiko offerings.

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.