Fortis Marinemaster M-40vsSeiko Prospex Sea
The numbers, the dial colors, the calibers — laid out so you can stop flipping between tabs.
At a glance
12 of 29 specs differFull specifications
Case
5 specsCrystal & Dial
3 specsMovement
3 specsPricing
1 specsFollow this matchup
Get a note when Fortis Marinemaster M-40 vs Seiko Prospex Sea gets more votes, a community discussion, or a price drop. No account needed.
Owners + reviewers, side by side
Synthesized for each watch independently from owner discussions, enthusiast forums, written reviews, and video reviewers.
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.
The Seiko Prospex Sea is widely praised for its excellent value, solid build quality, and comfortable wearability, with many models featuring impressive lume and attractive dials. Owners and reviewers highlight the modern upgrades on classic designs, such as drilled lugs and reliable movements with hacking and hand-winding capabilities. Some models are noted for their refined case finishing and scratch resistance. Accuracy figures vary, with one owner reporting approximately 4 seconds fast per day, while others find the movements offer good performance for the price. Concerns raised by owners and reviewers include clasps that can feel generic or cheap, and lug widths that some find disproportionate to the case size on certain models. The thickness and weight of some Prospex Sea watches are also noted as substantial. The GMT function on specific models is considered secondary and difficult to read for true travel purposes.
More watches worth a look
Matched to the watches above on size, movement, style and price — microbrands first. Open any one to dig in.
People also compared
Comparisons nearby in the catalog — alternatives to the watches above paired against the matchup.












