How big is the Seiko Tuna SNE497?

It cannot be confirmed. Seiko has removed the reference from its site, and third-party listings disagree with each other, so this page does not quote a diameter. It is a large watch; the shroud makes it wider than the case underneath.

Does the Seiko SNE497 need a battery?

No. The solar caliber V157 charges from light and stores the energy in a cell, so it runs without winding or scheduled battery changes.

Is the Seiko SNE497 a real dive watch?

Yes. It is a Prospex with a 200m diver’s rating, a unidirectional bezel and a crown protected by the shroud.

Is the Seiko SNE497 still made?

No. Seiko’s regional sites return nothing for the reference, and it is sold from remaining retailer and Amazon stock.

Illustrative render — hero view of the Seiko Prospex Solar “Tuna” SNE497

Seiko · Prospex Solar · Ref SNE497P1

The tin can that never needs a battery.

A black shroud wraps the whole case and hides the crown at four, which is the silhouette collectors call the Tuna. Inside is Seiko’s solar caliber V157, rated for 200m diving and charged by whatever light reaches the dial.

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Water resistance

200m diver’s

https://www.seikowatches.com/se-en/products/prospex/sne497

Movement

Solar V157

https://strapsco.com/seiko-sne497-lug-width-strap-size/

Case

Steel + shroud

Black resin shroud over stainless steel, crown at four

Crystal

Hardlex

Seiko hardened mineral glass

Lug width

22mm

https://strapsco.com/seiko-sne497-lug-width-strap-size/

Why the shroud

Seiko built the first shrouded diver in 1975 for professional saturation divers, and the outer guard that protects the case and crown gave the family its nickname. The SNE497 borrowed that silhouette for an entry-level solar diver.

The shroud is black resin over a steel case. The crown sits at four o’clock, fully enclosed, so there is nothing to knock. It is a working design, and it looks like one.

Illustrative render — why the shroud of the Seiko Prospex Solar “Tuna” SNE497

Solar V157

The V157 is the solar quartz caliber Seiko uses across its solar Prospex divers. A cell under the dial charges from light and stores it, so there is no winding and no battery to change on a schedule.

It drives hours, minutes, seconds and a date at four o’clock. The dial is black with round lumed markers and a lumed triangle at twelve, with SOLAR and DIVER’S 200m printed below centre.

Illustrative render — solar v157 of the Seiko Prospex Solar “Tuna” SNE497

What we cannot confirm

Seiko has removed this reference from its website in every region we checked, so there is no manufacturer figure for the case diameter. Retailers quote different numbers and Amazon quotes another, so this page prints none of them. Expect a large, tall watch; the shroud adds width to whatever the case measures.

Everything else here comes from Seiko’s general V157 specifications and from the reference itself. Nothing has been measured by us.

Illustrative render — what we cannot confirm of the Seiko Prospex Solar “Tuna” SNE497

Specs

Reference: SNE497P1
Movement: Solar Quartz V157
Caliber type: Seiko Solar Quartz
Crystal: Hardlex
Water resistance: 200m Diver
Complications: Date, Unidirectional Bezel, Shrouded Case
Origin: Seiko (Japan)

Specifications as published by Seiko. We research from manufacturer documentation and published sources rather than hands-on testing. Researched 2026-09-03.

Verdict

The cheapest route to the shrouded Tuna silhouette, with a 200m diver’s rating and a solar movement that removes the battery question.

Strengths

The shrouded case is unmistakable and protects the crown completely
200m diver’s rating on a Prospex
Solar V157: no winding, no scheduled battery changes
22mm lugs take a wide range of straps

Trade-offs

Discontinued by Seiko; stock is retailer-dependent
Case diameter cannot be verified against the manufacturer
Large and tall by design
Hardlex rather than sapphire

Buy it if

Someone who wants the professional-diver look and a watch that just runs, without caring about a mechanical movement.

Skip it if

You have a small wrist, want something slim, or need a figure for the case size before you buy.

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FAQ

The shrouded case looks like a tin of tuna. Collectors gave the name to Seiko’s original 1975 shrouded professional divers, and it has attached to every shrouded model since.

Sources

Researched and last updated 2026-09-03. We do not test watches in hand; every figure above is traceable to the manufacturer or the sources listed here.

Seiko Prospex Solar “Tuna” SNE497

Reference SNE497P1

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Prices and availability change; the band above is a research figure, so check the current listing.

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