Side by side

Marnaut Safe Harbour 100CvsSeiko Prospex Sea

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

Safe Harbour 100C
MarnautSafe Harbour 100C
MSRP $899
Prospex Sea
SeikoProspex Sea
MSRP $1,500
What people say

Owners + reviewers, side by side

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

Marnaut Safe Harbour 100C

The Marnaut Safe Harbour is widely praised for its compact 39mm tonneau case and its unique sea urchin-inspired dial. Reviewers note the case wears well despite its 13.2mm thickness. One owner flagged a potential lume inconsistency, which was attributed to UV lighting effects. The slender handset can be difficult to read against the busy dial, and the faux-crocodile strap is stiff initially. Overall, owners and reviewers appreciate the Marnaut Safe Harbour for its distinctive dial and comfortable wearability.

Seiko Prospex Sea

Seiko Prospex Sea owners and reviewers praise its Marinemaster-style aesthetic, excellent case finishing, and impressive LumiBrite lume. The watch is powered by the 6R15 movement with a 50-hour power reserve and comes with both a steel bracelet and a silicone strap. Some owners find the Seiko Prospex Sea to be a great value and a suitable first "proper" watch, while others report it is uncomfortably big, thick, and heavy on smaller wrists. Reviewers note the GMT function is secondary with a less prominent scale, and the bezel's quieter clicks may not appeal to all. On balance, owners and reviewers rate the Seiko Prospex Sea highly for its classic design and finishing at its price point.

At a glance

13 of 29 specs differ
Diameter
Safe Harbour 100C39mm
Prospex Sea43.5mm
Power Reserve
Safe Harbour 100C41h
Prospex Sea70h
Water Resistance
Safe Harbour 100C100m
Prospex Sea200m
MSRP
Safe Harbour 100C$899
Prospex Sea$1,500

Full specifications

Case

7 specs
Category
Diver
Diameter
39mm
43.5mm
Thickness
13mm
13.3mm
Lug-to-Lug
45mm
51mm
Lug Width
20mm
22mm
Material
Stainless Steel
Titanium
Water Resistance
100m
200m

Crystal & Dial

2 specs
AR Coating
Inner
Anti-reflective coating on inner surface
Lume
None
LumiBrite on hands and index(es)

Movement

3 specs
Caliber
Sellita SW200-1
Seiko 6R35
Power Reserve
41h
70h
Jewels
25
24

Pricing

1 specs
MSRP
$899
$1,500
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