Horlobase
enfrde

Seiko · Prospex

Seiko Prospex Sea SPB101

Reference SPB101J1 · Dive · 45 mm

102030405014Ø 45 mmLug-to-lug 52.6 mm
Illustration drawn from the specifications: case to scale, colours and style approximate. Not a photo. Photos on the official page

Specifications

Reference
SPB101J1
Family
Prospex
Category
Dive
Status
Current
Case material
Stainless steel
Case diameter
45 mm
Case thickness
12.9 mm Official
Lug-to-lug
52.6 mm Official
Lug width
20 mm Official
Water resistance
200 m
Bezel
Rotating, diver
Calibre
6R35 Official
Power reserve
about 70 h

Official product page · retrieved October 14, 2026

Does it fit your wrist?

Enter your wrist circumference. The watch appears to scale on the flat top of the wrist.

102030405014Lug-to-lug 52.6 mmFlat top of the wrist 54.1 mm
Top view on a wrist, to scale
Flat top of the wrist 54.1 mmLug-to-lug 52.6 mmCase diameter 45 mm
Side view, across the wrist

At the limit

Lug-to-lug 52.6 mm on a flat top of 54.1 mm: 97 % of the width.

Lug-to-lug is 95 to 100% of the flat top. The lugs reach the edge, so check your wrist shape.

Measurements and sources

Brands rarely publish thickness, lug width and lug-to-lug together. Each observation below is kept separate, with who gave it.

Case thickness

Value Type Source Date
12.9 mm Official Seiko October 14, 2026

Lug-to-lug

Value Type Source Date
52.6 mm Official Seiko October 14, 2026

Lug width

Lug width is the gap between the lugs, where the strap fits. It is not lug-to-lug.

Value Type Source Date
20 mm Official Seiko October 14, 2026

Calibre source

Official Seiko · retrieved October 14, 2026

Other versions in the same case

These references differ only by dial, bracelet or bezel colour. The brand gives them the same case dimensions, so the figures on this page apply to them too.

Other Prospex references

Watch Ø Thickness Lug-to-lug Calibre
Prospex Sea SPB077 1968 Diver's Modern Re-interpretation SPB077J1 44 mm 12.7 mm 51 mm 6R15
Prospex Sea SPB189 Titanium SPB189J1 43.5 mm 13.3 mm 51 mm 6R35
Prospex Sea SPB153 1970 Heritage Diver's SPB153J1 42.7 mm 13.2 mm 46.6 mm 6R35
Prospex Marinemaster 1968 Heritage Diver's SLA077 SLA077J1 42.6 mm 13.4 mm 49.3 mm 8L35
Prospex Sea SPB481 SPB481J1 41.3 mm 12.5 mm 48.2 mm 6R55
Prospex Sea SPB317 SPB317J1 41 mm 12.3 mm 46.9 mm 6R35
Prospex Sea SPB145 1965 Heritage Diver's SPB145J1 40.5 mm 13.2 mm 47.6 mm 6R35
Prospex SPB453 1965 Heritage Diver's SPB453J1 40 mm 13 mm 46.4 mm 6R55
Prospex Marinemaster 1965 Heritage Diver's SJE099J1 39.5 mm 12.3 mm 47.2 mm 6L37
Prospex Sea SPB519 1968 Heritage Diver's GMT SPB519J1 42 mm 13.3 mm 48.6 mm 6R54
Prospex Land SPB209 SPB209J1 39.5 mm 13.2 mm 46.4 mm 6R35
Prospex Land SPB377 Mechanical GMT SPB377J1 39.5 mm 13.6 mm 46.4 mm 6R54
Prospex Land SPB503 SPB503J1 39.5 mm 12.7 mm 46.4 mm 6R55
Prospex Land SPB155 SPB155J1 38 mm 12.9 mm 46 mm 6R35
Prospex Land SPB241 SPB241J1 38 mm 12.9 mm 46.2 mm 6R35
Prospex Speedtimer SRQ047 Mechanical Chronograph SRQ047J1 42 mm 14.6 mm 49.5 mm 8R48
Prospex Speedtimer SPB513 Mechanical SPB513J1 39.5 mm 12 mm 44.5 mm 6R55

Other Seiko models

Watch Ø Thickness Lug-to-lug Calibre
Seiko 5 Sports SKX GMT SSK001 SSK001 42.5 mm 13.6 mm 46 mm 4R34
Presage Style60's GMT SSK013 SSK013J1 40.8 mm 13 mm 47 mm 4R34
Seiko 5 Sports Field GMT SSK023 SSK023 39.4 mm 13.6 mm 47.9 mm 4R34
Presage Cocktail Time SRPB41 SRPB41J1 40.5 mm 11.8 mm — 4R35
Presage Classic Series SPB463 SPB463J1 40.2 mm 13 mm 46 mm 6R55
Presage Sharp Edged Series SPB165 SPB165J1 39.3 mm 11.1 mm 47.2 mm 6R35

← All watches