Seiko Prospex SeavsLongines ULTRA‑CHRON CARBON

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Measurements

Catalog photos are all shot at the same flattering size. These aren't: every case below shares one millimeter scale.

Seiko Prospex Sea at true scale

Prospex Sea

Longines ULTRA‑CHRON CARBON at true scale

ULTRA‑CHRON CARBON

Diameter

43.8mm

43mm

Lug-to-Lug

48.7mm

lowest

48.9mm

Thickness

12.8mm

lowest

14mm

Water Resistance

200m

300m

highest

Power Reserve

41h

52h

highest

MSRP

$625

lowest

$5,550

Movement

Seiko 4R35

Longines L836.6

Case

6 specs
Diameter
43.8mm
43mm
Thickness
12.8mm
14mm
Lug-to-Lug
48.7mm
48.9mm
Material
Stainless Steel
Titanium
Water Resistance
200m
300m
Caseback
n/a
Screw-down case back

Crystal & Dial

4 specs
AR Coating
Anti-reflective coating on inner surface
Both sides
Dial Color
n/a
Silver
Indices
n/a
Applied indexes
Lume
LumiBrite on hands, index(es) and bezel
Super-LumiNova

Movement

5 specs
Caliber
Seiko 4R35
Longines L836.6
Beat Rate
0 vph
36,000 vph
Power Reserve
41h
52h
Jewels
23
0
Complications
None
Hours, minutes, seconds

Pricing

1 specs
MSRP
$625
$5,550
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Reviews

Synthesized for each watch independently from owner discussions, enthusiast forums, written reviews, and video reviewers.

Seiko Prospex Sea

The Seiko Prospex Sea is widely praised for its excellent value as a sport watch, with owners highlighting its comfortable wearability and generous lume. Reviewers note its solid build quality and attractive design, with some specifically mentioning the matte black dial as a strong point. One owner reports accuracy around +1 to +2 seconds per day. The 43.8mm case size is considered substantial by some, and one owner found the watch heavy and thick, regretting not choosing a different variant. Overall, owners and reviewers rate the Seiko Prospex Sea highly for its blend of classic design and modern utility at an accessible price point.

Longines ULTRA‑CHRON CARBON

Owners praise the Longines ULTRA‑CHRON CARBON for its unique "Batman" aesthetic and lightweight composite case, which weighs only 80 grams. The high-beat L836.6 movement is noted for exceptional accuracy, with one owner calling it the cheapest 5Hz option available. The non-rotating bezel is a point of contention, with some finding it a welcome feature and others considering it a deal-breaker that removes its dive watch functionality. On balance, owners and reviewers find the Longines ULTRA‑CHRON CARBON a surprisingly cool and lightweight watch, with its accurate 5Hz movement being a significant draw.