Which is cheaper, the Seiko Prospex Sea or the Undone Popeye Mono Automatic?

At MSRP the Undone Popeye Mono Automatic is the cheaper of the two at $499, against $900 for the Seiko Prospex Sea — a $401 gap before any retailer discounting.

Which is bigger, the Seiko Prospex Sea or the Undone Popeye Mono Automatic?

The Seiko Prospex Sea wears larger at 41mm versus 40mm for the Undone Popeye Mono Automatic — a 1mm difference across the dial.

Which has better water resistance, the Seiko Prospex Sea or the Undone Popeye Mono Automatic?

The Seiko Prospex Sea is rated to 200m versus 100m for the Undone Popeye Mono Automatic.

What movement does the Seiko Prospex Sea run compared to the Undone Popeye Mono Automatic?

Both watches run automatic movements — the Seiko Prospex Sea uses the Seiko 6R35 and the Undone Popeye Mono Automatic uses the Seiko NH35.

Side by side

Seiko Prospex SeavsUndone Popeye Mono Automatic

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

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Seiko Prospex Sea

MSRP $900

See the full Prospex Sea

Undone Popeye Mono Automatic

MSRP $499

See the full Popeye Mono Automatic

At a glance

15 of 29 specs differ

Diameter

Prospex Sea41mm

Popeye Mono Automatic40mm

Power Reserve

Prospex Sea70h

Popeye Mono Automatic—

Water Resistance

Prospex Sea200m

Popeye Mono Automatic100m

MSRP

Prospex Sea$900

Popeye Mono Automatic$499

Full specifications

Case

6 specs

Crystal & Dial

5 specs

Crystal

Sapphire

—

Crystal Shape

Curved

—

AR Coating

Anti-reflective coating on inner surface

—

Dial Color

—

Lume

LumiBrite on hands, index(es) and bezel

None

Movement

3 specs

Caliber

Seiko 6R35

Seiko NH35

Power Reserve

70h

—

Jewels

Pricing

1 specs

MSRP

$900

$499

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Seiko Prospex SeavsUndone Popeye Mono Automatic

At a glance

Full specifications

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