Which is cheaper, the Seiko Prospex Sea or the Spinnaker Croft Mid-Size Skeleton?

At MSRP the Spinnaker Croft Mid-Size Skeleton is the cheaper of the two at $425, against $900 for the Seiko Prospex Sea — a $475 gap before any retailer discounting.

Which is bigger, the Seiko Prospex Sea or the Spinnaker Croft Mid-Size Skeleton?

The Seiko Prospex Sea wears larger at 41mm versus 40mm for the Spinnaker Croft Mid-Size Skeleton — a 1mm difference across the dial.

Which has better water resistance, the Seiko Prospex Sea or the Spinnaker Croft Mid-Size Skeleton?

The Seiko Prospex Sea is rated to 200m versus 100m for the Spinnaker Croft Mid-Size Skeleton.

Which has a longer power reserve, the Seiko Prospex Sea or the Spinnaker Croft Mid-Size Skeleton?

The Seiko Prospex Sea carries a 70-hour power reserve against 40 hours on the Spinnaker Croft Mid-Size Skeleton.

What movement does the Seiko Prospex Sea run compared to the Spinnaker Croft Mid-Size Skeleton?

Both watches run automatic movements — the Seiko Prospex Sea uses the 6R35 and the Spinnaker Croft Mid-Size Skeleton uses the SII NH38A.

Side by side

Seiko Prospex SeavsSpinnaker Croft Mid-Size Skeleton

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

Seiko Prospex Sea

spb317j1

MSRP $900

Spinnaker Croft Mid-Size Skeleton

croft-mid-size-skeleton-automatic-spongebob-squarepants-peek-a-boo-limited-edition-dollar-diver-sp-5152-01

MSRP $425

At a glance

14 of 29 specs differ

Diameter

Prospex Sea41mm

Croft Mid-Size Skeleton40mm

Power Reserve

Prospex Sea70h

Croft Mid-Size Skeleton40h

Water Resistance

Prospex Sea200m

Croft Mid-Size Skeleton100m

MSRP

Prospex Sea$900

Croft Mid-Size Skeleton$425

Full specifications

Case

6 specs

Crystal & Dial

4 specs

Crystal Shape

Curved

Flat

AR Coating

Anti-reflective coating on inner surface

Inner

Dial Color

Black

Dollar Diver

Lume

LumiBrite on hands, index(es) and bezel

None

Movement

3 specs

Caliber

6R35

SII NH38A

Power Reserve

70h

40h

Jewels

Pricing

1 specs

MSRP

$900

$425

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What people say

Owners + reviewers, side by side

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

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.

Spinnaker Croft Mid-Size Skeleton

The Spinnaker Croft Mid-Size Skeleton is noted for its 40mm steel case, sapphire crystal, and 150m water resistance. One owner reports strong performance from the TMI NH70 movement at -3 seconds per day, with very nice lume. On balance, owners find the Spinnaker Croft Mid-Size Skeleton to be a pretty nice option, particularly for its movement performance and lume.

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