Side by side

Fortis Marinemaster M-40vsSeiko Prospex Sea Seiko Prospex 1965 Heritage Diver’s Watch Save the Ocean Limited Edition

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

At a glance

10 of 29 specs differ
Diameter
Marinemaster M-4040mm
Prospex Sea Seiko Prospex 1965 Heritage Diver’s Watch Save the Ocean Limited Edition40mm
Power Reserve
Marinemaster M-4038h
Prospex Sea Seiko Prospex 1965 Heritage Diver’s Watch Save the Ocean Limited Edition72h
Water Resistance
Marinemaster M-40300m
Prospex Sea Seiko Prospex 1965 Heritage Diver’s Watch Save the Ocean Limited Edition300m
MSRP
Marinemaster M-40$3,520
Prospex Sea Seiko Prospex 1965 Heritage Diver’s Watch Save the Ocean Limited Edition$1,400

Full specifications

Case

2 specs
Lug-to-Lug
46.4mm
Lug Width
21mm
20mm

Crystal & Dial

4 specs
Crystal Shape
Flat
Curved
AR Coating
Inner
Anti-reflective coating on inner surface
Dial Color
Orange
Black
Lume
None
LumiBrite on hands, index(es) and bezel

Movement

3 specs
Caliber
Sellita SW220-1
6R55
Power Reserve
38h
72h
Jewels
26
24

Pricing

1 specs
MSRP
$3,520
$1,400

Follow this matchup

Get a note when Fortis Marinemaster M-40 vs Seiko Prospex Sea Seiko Prospex 1965 Heritage Diver’s Watch Save the Ocean Limited Edition 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.

Fortis Marinemaster M-40

Owners praise the Fortis Amber Orange for its gorgeous appearance and strong wrist presence, noting its crazy lume and 70-hour power reserve. The Doxa SUB 300T, described as having a superb, eccentric design with a highly legible dial and functional no-decompression bezel, uses an ETA 2824-2 movement. However, the SUB 300T's 42.5mm case wears large and its 14mm thickness is not ideal for dress shirts, though it boasts 1,200m water resistance. On balance, owners appreciate the Fortis Amber Orange for its striking aesthetics and impressive lume.

Seiko Prospex Sea Seiko Prospex 1965 Heritage Diver’s Watch Save the Ocean Limited Edition

The Prospex Sea Seiko Prospex 1965 Heritage Diver’s Watch Save the Ocean Limited Edition is praised for its compact 40mm case and the new Caliber 6R55 movement offering a 72-hour power reserve. Owners and reviewers highlight the stunning dials as a strong suit for Seiko. However, the 6R movement's accuracy is a point of disappointment for some, who wish for improvements closer to other movements, though others accept it given the excellent overall package. Press images suggest the bracelet end links may appear disjointed. Overall, owners and reviewers rate the Prospex Sea Seiko Prospex 1965 Heritage Diver’s Watch Save the Ocean Limited Edition well, with the stunning dials and improved power reserve being the biggest reasons.

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.