Steinhart Ocean One vs Seiko Prospex King Turtle SRPE05

Both are dive watches in the mid tier. In short: the Steinhart Ocean One takes more water (300m) — both are fine for swimming, but it has more margin if you dive. The Steinhart Ocean One is automatic, 300m water resistance, 42mm, sapphire crystal; the Seiko Prospex King Turtle SRPE05 is automatic, 200m water resistance, 45mm, sapphire crystal.

Last verified 2026-06-27 · specs from manufacturer data · tier = price band, confirm the live price at the retailer

Spec	Steinhart Ocean One	Seiko Prospex King Turtle SRPE05
Movement	Automatic	Automatic
Water resistance	300m	200m
Case size	42mm	45mm
Crystal	sapphire	sapphire
Style	Dive	Dive
Price tier	Mid	Mid

Which should you buy?

The Steinhart Ocean One takes more water (300m) — both are fine for swimming, but it has more margin if you dive
The Steinhart Ocean One wears 42mm vs the Seiko Prospex King Turtle SRPE05's 45mm — choose by wrist size

Where to buy

Steinhart Ocean OneSee price on AmazonCheck price

Seiko Prospex King Turtle SRPE05See price on AmazonCheck price

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FAQ

What's the difference between the Steinhart Ocean One and the Seiko Prospex King Turtle SRPE05?
Both are dive watches in the mid tier. The Steinhart Ocean One is automatic, 300m water resistance, 42mm, sapphire crystal; the Seiko Prospex King Turtle SRPE05 is automatic, 200m water resistance, 45mm, sapphire crystal.

Which has better water resistance, the Steinhart Ocean One or the Seiko Prospex King Turtle SRPE05?
The Steinhart Ocean One, rated 300m, versus 200m on the other. Pick 100m or higher for swimming and 200m+ for diving.

Which is better value, the Steinhart Ocean One or the Seiko Prospex King Turtle SRPE05?
Both sit in the mid tier, so it comes down to movement, water resistance and case size — see the spec table above.

Citing these specs? Go ahead — manufacturer data, last verified 2026-06-27. Copy a ready-made reference:

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