Which is cheaper, the Borealis Watch Co. Neptuno or the Seiko Prospex Sea The Black Series?

At MSRP the Borealis Watch Co. Neptuno is the cheaper of the two at $390, against $765 for the Seiko Prospex Sea The Black Series — a $375 gap before any retailer discounting.

Which is bigger, the Borealis Watch Co. Neptuno or the Seiko Prospex Sea The Black Series?

The Seiko Prospex Sea The Black Series wears larger at 45mm versus 40.00mm for the Borealis Watch Co. Neptuno — a 5mm difference across the dial.

Which has better water resistance, the Borealis Watch Co. Neptuno or the Seiko Prospex Sea The Black Series?

The Borealis Watch Co. Neptuno is rated to 300m versus 200m for the Seiko Prospex Sea The Black Series.

Which has a longer power reserve, the Borealis Watch Co. Neptuno or the Seiko Prospex Sea The Black Series?

The Seiko Prospex Sea The Black Series carries a 41-hour power reserve against 40 hours on the Borealis Watch Co. Neptuno.

What movement does the Borealis Watch Co. Neptuno run compared to the Seiko Prospex Sea The Black Series?

Both watches run automatic movements — the Borealis Watch Co. Neptuno uses the NH38 and the Seiko Prospex Sea The Black Series uses the 4R36.

Side by side

Borealis Watch Co. NeptunovsSeiko Prospex Sea The Black Series

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

Borealis Watch Co.Neptuno

borealis-neptuno-red-fade-to-black-dial-no-date-nh38-automatic-movement-300m-diver-watch

MSRP $390

Seiko Prospex Sea The Black Series

srpk43

MSRP $765

At a glance

11 of 29 specs differ

Diameter

Neptuno40.00mm

Prospex Sea The Black Series45mm

Power Reserve

Neptuno40h

Prospex Sea The Black Series41h

Water Resistance

Neptuno300m

Prospex Sea The Black Series200m

MSRP

Neptuno$390

Prospex Sea The Black Series$765

Full specifications

Case

5 specs

Diameter

40.00mm

45mm

Thickness

14.10mm

13.2mm

Lug-to-Lug

47.20mm

47.7mm

Lug Width

20mm

22mm

Water Resistance

300m

200m

Crystal & Dial

2 specs

AR Coating

Inner

Anti-reflective coating on inner surface

Lume

BGW9

LumiBrite on hands, index(es) and bezel

Movement

3 specs

Caliber

NH38

4R36

Power Reserve

40h

41h

Jewels

Pricing

1 specs

MSRP

$390

$765

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