Seamaster Diver 300M Automatic 28 Yellow Gold / White / Bracelet

In Context

At 28 mm it is small by current standards, in the range most wristwatches occupied before cases began growing through the 1990s. The case back is closed, so the movement stays out of sight, and the sapphire crystal will resist everything short of deliberate abuse. 300 m is a professional diving rating, far past any demand a wrist is likely to make of it.

The movement winds itself from the motion of your wrist. 42 hours of reserve carries it overnight, but not through a weekend in a drawer. At 28,800 vph the seconds hand advances 8 times a second.

2172.70.00 stands on its own in this catalogue — no other reference here shares its base number. It pairs a white dial with a yellow gold case.

The 2520 is Omega's small automatic of the 1990s and 2000s, an ETA 2000-1 with a rhodium-plated finish for the 27 mm to 29 mm ladies' cases. It powers 24 watches in this library. The ETA 2000 is the smallest of ETA's standard automatics, 19.4 mm across, and Omega's version runs at 28,800 vph with a 42-hour reserve and 20 jewels. It is the movement that gave the small Constellation and Aqua Terra a mechanical option beside the quartz calibers, in the years before Omega's own [8520](/calibers/omega-8520) arrived in 2010. In the library it powers 15 [Constellation](/brands/omega/constellation) references at 27.5 mm, including the "My Choice" models of the Cindy Crawford years, 7 [Aqua Terras](/brands/omega/aqua-terra) at 29.2 mm, one De Ville and one Seamaster Diver 300M. The [1376](/calibers/omega-1376) and [1456](/calibers/omega-1456) are the quartz movements of the same small Constellations, and the 8520 the in-house automatic that succeeded it.

23 other watches in the library run the Omega 2520.

Omega

Seamaster Aqua Terra 150M Automatic 29.2 Stainless Steel / Red Gold / Diamond / MOP / Bracelet

2365.75.00 · 29.2 mm

Omega

Seamaster Aqua Terra 150M Automatic 29.2 Stainless Steel / Red Gold / MOP / Bracelet

2373.70.00 · 29.2 mm

Omega

Seamaster Aqua Terra 150M Automatic 29.2 Stainless Steel / Diamond / MOP / Bracelet

2564.75.00 · 29.2 mm

Omega

Seamaster Aqua Terra 150M Automatic 29.2 Stainless Steel / MOP / Bracelet

2573.70.00 · 29.2 mm