Best 40mm watches

A 300m diver's watch in a 40mm case with a 46.4mm lug-to-lug, sapphire and a 72-hour 6R55 with a published accuracy tolerance.

13mm thick. Seiko's warranty is three years, and the published $296 6R overhaul is the running cost.

300m and a 46.4mm lug-to-lug in the same watch is unusual. The extender in the clasp is the detail that says Seiko still expects this one to be dived, not just worn.

The Presage with a Prospex specification: sapphire, 100m, a 72-hour 6R5J and a published +25/-15 seconds a day, at 40.2mm and 46mm lug-to-lug.

13mm thick — dressy rather than a dress watch.

This is the Presage with the Prospex specification sheet: dual-curved sapphire, 100m, 72 hours and a published +25 to -15 seconds a day, on the 6R family's published $296 service path. It is 13mm thick, which is the price of all that on a dress watch.

Sapphire, 100m and 80 hours at 40mm and 11.5mm, on a bracelet that comes off without a tool.

Tissot does not publish its lug-to-lug, and the lug width is 21mm.

The quick-release bracelet is the detail worth paying for: this is one of the few Swiss automatics at this level you can re-strap in thirty seconds without a tool.

A 42mm lug-to-lug is the shortest on this page by a distance — a 40mm watch that sits on less wrist than the 38mm Khaki Field.

It is a skeleton, rated 50m, on an 80-hour H-10-S.

42mm lug-to-lug on a 40mm case is remarkable — this is a skeleton watch that actually fits a normal wrist. 50m is the honest limit: an open dial is still a sealed case, but it is not a watch to swim in.

Under 11mm with sapphire, 100m and an 80-hour Powermatic 80, backed by Tissot's published $210 service price.

The 12mm bracelet fitting is not a strap size, and Tissot does not publish the lug-to-lug.

Tissot publishes a US complete-service price of $210 for a mechanical two-or-three-hand watch, which makes this the most predictable Swiss automatic here to own. The 12mm lug width is not a strap size — the bracelet is part of the case.

The Cocktail Time with its lug-to-lug published — 47.5mm — on the 4R35 and Seiko's $176 overhaul, with three years of warranty.

A box-shaped Hardlex crystal and 50m.

The same 4R35 and the same $176 published overhaul as the rest of the Cocktail Time line, with the lug-to-lug published — 47.5mm — so you can check the fit before buying. 50m and Hardlex are the dress-watch trade.

A 40mm solar field watch 10.4mm thick, with sapphire, a screw-down crown and 100m.

Two years of warranty. Sold direct; we earn nothing on this link.

Sapphire, a locking screw-down crown, 100m and a published accuracy of -10/+20 seconds a month in a case 10.4mm thick. Vaer states it is assembled in the United States. Sold direct; we earn nothing on it.