The Titanium Field Guide

Seiko Prospex Marinemaster Professional 1000m Emperor Tuna SLA042

SLA042 / SBDX038

The Seiko Prospex Marinemaster Professional 1000m Emperor Tuna SLA042 is a current-production diver watch with a titanium (grade undisclosed) case, finished with ceramic outer shroud. It is priced well above the $1,299 median for the category.

All Seiko watchesWatch diver watches
Price
$3,200
Material
Titanium
Grade / type
Titanium (grade undisclosed)
Water resistance
1000 m
Reference
SLA042 / SBDX038
Type
Diver
Case diameter
52.4 mm
Origin
Japan
Movement
Automatic
Caliber
8L35
Power reserve
50h
Complications
Date
Colour
Grey
Surface treatment
Ceramic outer shroud
Finish technology
Natural finish
Caseback
Titanium
Nickel-free
Unconfirmed (bracelet, strap, or clasp hardware not confirmed)
Bracelet / strap
Black silicone strap
Crystal
Sapphire
Display back
No
Dial
Black
Dial colours
Black
Lume
LumiBrite
Availability
Offered
Status
Current
Not published
Thickness, Lug-to-lug, Weight, Hardness, Construction, Matching bracelet
Medium confidence Verified Jul 2026 Source: Seiko (Prospex SLA042)
Facts are free to cite with a link.
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Frequently asked questions

What is the case material of the Seiko Prospex Marinemaster Professional 1000m Emperor Tuna SLA042?

The Seiko Prospex Marinemaster Professional 1000m Emperor Tuna SLA042 has a titanium (grade undisclosed) case with a titanium caseback. It is recorded at medium confidence pending a maker-stated material.

What size is the Seiko Prospex Marinemaster Professional 1000m Emperor Tuna SLA042?

It is 52.4 mm in diameter, and water resistant to 1000 m.

How much does the Seiko Prospex Marinemaster Professional 1000m Emperor Tuna SLA042 cost, and is it available?

It is current-production and lists from $3,200.

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