Side by side

Borealis Watch Co. Estoril 300 GMTvsSeiko Prospex Sea

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

Estoril 300 GMT
Borealis Watch Co.Estoril 300 GMT
MSRP $600
Prospex Sea
SeikoProspex Sea
MSRP $900
What people say

Owners + reviewers, side by side

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

Borealis Watch Co. Estoril 300 GMT

Owners widely praise the Borealis Watch Co. Estoril 300 GMT for its excellent value, robust build quality, and crisp dial, with reviewers highlighting its exceptionally bright BGW9 lume and dive-ready ceramic bezel. Some owners appreciate the brushed and polished finishes, though one owner noted a desire for a white-painted second hand. The included NATO strap is considered too thick with a loose weave, and the sapphire bezel insert is seen by some as a minor aesthetic departure from its inspirations. Overall, owners rate the Borealis Watch Co. Estoril 300 GMT highly for its impressive build quality and value.

Seiko Prospex Sea

Owners widely praise the Seiko Prospex Sea for its excellent lume, robust build, and value, with many highlighting the comfortable 4 o'clock crown and reliable movements. Reviewers note impressive case finishing and attractive dials, with specific models lauded for their gradient blue designs and smooth bezel actions. Accuracy figures vary, with one owner reporting +9 seconds/day after demagnetization, while others find the watches to be good first "proper" watches. Some owners find the stock rubber straps uncomfortable or the overall size substantial on smaller wrists. On balance, owners and reviewers rate the Seiko Prospex Sea highly for its combination of strong dive watch functionality and appealing design at its price point.

At a glance

12 of 29 specs differ
Diameter
Estoril 300 GMT41.50mm
Prospex Sea41mm
Power Reserve
Estoril 300 GMT40h
Prospex Sea70h
Water Resistance
Estoril 300 GMT300m
Prospex Sea200m
MSRP
Estoril 300 GMT$600
Prospex Sea$900

Full specifications

Case

5 specs
Diameter
41.50mm
41mm
Thickness
13.5mm
12.3mm
Lug-to-Lug
47mm
46.9mm
Lug Width
20mm
20mm
Water Resistance
300m
200m

Crystal & Dial

3 specs
Crystal Shape
Flat
Curved
AR Coating
Inner
Anti-reflective coating on inner surface
Lume
BGW9
LumiBrite on hands, index(es) and bezel

Movement

3 specs
Caliber
Miyota 9075
6R35
Power Reserve
40h
70h
Jewels
25
24

Pricing

1 specs
MSRP
$600
$900
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