Which is cheaper, the Lum-Tec B66 Day Date or the Seiko Prospex Sea?

At MSRP the Lum-Tec B66 Day Date is the cheaper of the two at $545, against $625 for the Seiko Prospex Sea — a $80 gap before any retailer discounting.

Which is bigger, the Lum-Tec B66 Day Date or the Seiko Prospex Sea?

The Lum-Tec B66 Day Date wears larger at 44mm versus 43.8mm for the Seiko Prospex Sea — a 0.2mm difference across the dial.

Which has better water resistance, the Lum-Tec B66 Day Date or the Seiko Prospex Sea?

The Seiko Prospex Sea is rated to 200m versus 100m for the Lum-Tec B66 Day Date.

Which has a longer power reserve, the Lum-Tec B66 Day Date or the Seiko Prospex Sea?

The Seiko Prospex Sea carries a 41-hour power reserve against 40 hours on the Lum-Tec B66 Day Date.

Side by side

Lum-Tec B66 Day DatevsSeiko Prospex Sea

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

Lum-Tec B66 Day Date

b66-day-date

MSRP $545

Seiko Prospex Sea

srpe37

MSRP $625

At a glance

14 of 29 specs differ

Diameter

B66 Day Date44mm

Prospex Sea43.8mm

Power Reserve

B66 Day Date40h

Prospex Sea41h

Water Resistance

B66 Day Date100m

Prospex Sea200m

MSRP

B66 Day Date$545

Prospex Sea$625

Full specifications

Case

6 specs

Crystal & Dial

4 specs

Crystal

Domed Sapphire

Sapphire

AR Coating

Inner

Anti-reflective coating on inner surface

Dial Color

Standard

Black

Lume

None

LumiBrite on hands, index(es) and bezel

Movement

3 specs

Caliber

—

4R35

Power Reserve

40h

41h

Jewels

Pricing

1 specs

MSRP

$545

$625

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Lum-Tec B66 Day DatevsSeiko Prospex Sea

At a glance

Full specifications

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