Seiko Prospex Turtle SRPE vs Seiko Prospex Samurai SRPB51

Both are dive watches in the mid tier. In short: the Seiko Prospex Turtle SRPE wears 45mm vs the Seiko Prospex Samurai SRPB51's 43.8mm — choose by wrist size. The Seiko Prospex Turtle SRPE is automatic, 200m water resistance, 45mm, hardlex crystal; the Seiko Prospex Samurai SRPB51 is automatic, 200m water resistance, 43.8mm, hardlex crystal.

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

Spec	Seiko Prospex Turtle SRPE	Seiko Prospex Samurai SRPB51
Movement	Automatic	Automatic
Water resistance	200m	200m
Case size	45mm	43.8mm
Crystal	hardlex	hardlex
Style	Dive	Dive
Price tier	Mid	Mid

Which should you buy?

The Seiko Prospex Turtle SRPE wears 45mm vs the Seiko Prospex Samurai SRPB51's 43.8mm — choose by wrist size.

Where to buy

Seiko Prospex Turtle SRPESee price on AmazonCheck price

Seiko Prospex Samurai SRPB51See price on AmazonCheck price

As an Amazon Associate we earn from qualifying purchases, at no extra cost to you. Affiliate links never affect our specs or which watches we compare.

Ordering a watch? Amazon Prime includes fast delivery on eligible items, and eligible new members may be offered a free trial. Delivery speed and return terms vary by item, so check the listing when sizing is a gamble. See if you can try Prime free →

Affiliate link — we may earn a commission on qualifying sign-ups, at no extra cost to you. Current terms are on Amazon's page.

Neither of these quite right? Answer five questions — wrist size, what it's for, battery or automatic, whether it gets wet, budget — and see which of the 128 watches actually fit →

FAQ

What's the difference between the Seiko Prospex Turtle SRPE and the Seiko Prospex Samurai SRPB51?
Both are dive watches in the mid tier. The Seiko Prospex Turtle SRPE is automatic, 200m water resistance, 45mm, hardlex crystal; the Seiko Prospex Samurai SRPB51 is automatic, 200m water resistance, 43.8mm, hardlex crystal.

Which is better value, the Seiko Prospex Turtle SRPE or the Seiko Prospex Samurai SRPB51?
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:

More dive comparisons: Casio Duro MDV106 (Marlin) vs Orient Ray II · Seiko Prospex Turtle SRPE vs Seiko Prospex Solar Tuna SNE575 · Christopher Ward C60 Trident vs Marathon TSAR · Seiko Prospex Sumo SPB103 vs Casio G-Shock Frogman GWF-A1000 · dive watches under ~$600 · all dive watches · all comparisons