5 Sports 38mm Automatic Watch

The Seiko 5 Sports 38mm Automatic Watch is a 38 mm, 100 m water-resistant automatic dive watch.

Case: 38 mm
Water: 100 m (328 ft)
Movement: Automatic
Thickness: 12.1 mm

What the data says

Lighter than 50% of the 12 other watches we list in the 36–40 mm range.
Lowest in-stock price is 38% below list price this week.

Computed from the specs below. How we write summaries.

Full specs

Last verified Oct 5, 2026

Seiko’s own site doesn’t allow automated reading, so specs, prices and photos come from Long Island Watch’s product page (longislandwatch.com), a retailer that sells it. Unless marked otherwise, every spec is quoted from that page.

Case
Case diameter	38 mm
Thickness	12.1 mm
Lug to lug	44.2 mm
Lug width	20 mm
Weight (manufacturer)	0.31 lb (140 g)
Case	Stainless steel
Strap	Stainless steel bracelet, deployant clasp, 20mm

Toughness
Water resistance	100 m (328 ft)

Movement & features
Movement	Automatic
Caliber	Seiko 4R36
Battery / power reserve	approximately 41-hour power reserve
Display	Analog
Style	Dive
Luminous hands/markers	Yes
Rotating bezel	Yes
Date	Yes