Formex Reef 39.5 mmvsSeiko Prospex Sea
lug2lug doesn't sell watches. Buy links open the brand's or seller's own site. Some links are affiliate links: lug2lug may earn a commission at no extra cost to you. Disclosures
Measurements
Catalog photos are all shot at the same flattering size. These aren't: every case below shares one millimeter scale.
Reef 39.5 mm
Prospex Sea
Diameter
39.5mm
41.7mm
Lug-to-Lug
45.5mm
lowest
49.5mm
Thickness
11mm
lowest
12.3mm
Water Resistance
300m
highest
200m
Power Reserve
56h
highest
41h
MSRP
$2,230
$595
lowest
Movement
Sellita SW300-1
Seiko 4R35
Case
5 specsCrystal & Dial
3 specsMovement
3 specsPricing
1 specsReviews
Synthesized for each watch independently from owner discussions, enthusiast forums, written reviews, and video reviewers.
The Formex Reef 39.5 mm is widely praised for its refined finishing, improved proportions, and compelling value under €2,000. Owners and reviewers highlight its comfortable wearability on smaller wrists, unique aesthetic, and impressive specifications including 300m water resistance and a COSC-certified Sellita SW300-1 movement. Some note the 22mm lug width feels slightly disproportionate and the bracelet could benefit from more taper. A prototype crown protrusion issue is expected to be resolved in production. Overall, owners rate the Formex Reef 39.5 mm highly for its excellent build quality and tool-like features at its price point.
Owners widely report the Seiko Prospex Sea is a well-built watch at a fair price, with some finding its 41.7mm case size perfect while others with smaller wrists consider it big, thick, and heavy. Reviewers consistently praise the excellent lume and robust design. One owner notes the bezel action is smoother and more precise than some other Seiko divers. Overall, owners and reviewers rate the Seiko Prospex Sea highly for its value and proven design.
Similar watches
Matched to the watches above on size, movement, style and price, microbrands first. Open any one to dig in.
Also compared
Comparisons nearby in the catalog: alternatives to the watches above paired against the matchup.