Seamaster Aqua Terra 150M Master Chronometer 38 Sedna Gold / Diamond / MOP / Alligator

In Context

At 38 mm it sits just under the modern norm — the band that suits the widest spread of wrists. The case back is open, so the movement is visible without taking the watch apart, and the sapphire crystal will resist everything short of deliberate abuse. 150 m is genuine swimming resistance — more than the shape of this watch suggests it would need.

The movement winds itself from the motion of your wrist. 55 hours of reserve is enough to set it down on Friday evening and find it still running on Monday. At 25,200 vph the seconds hand advances 7 times a second.

220.58.38.20.55.001 stands on its own in this catalogue — no other reference here shares its base number. It pairs a white dial with a sedna gold case. Introduced in 2002.

The 8801 is the 8800 with an 18-carat Sedna gold rotor and balance bridge. It is the version of Omega's mid-size Master Chronometer movement fitted to gold-cased watches. It powers 26 watches in this library. The [8800](/calibers/omega-8800) is a single-barrel co-axial caliber certified by METAS to resist 15,000 gauss, with a silicon balance spring, a free-sprung balance, 35 jewels, a 55-hour reserve and a beat of 25,200 vph. The 8801 is mechanically the same; the rotor and the balance bridge are made in Sedna gold, Omega's red gold alloy, so the movement seen through a display back matches the case. The [8807](/calibers/omega-8807) is the same idea in the Aqua Terra, and the [8901](/calibers/omega-8901) the gold version of the larger 8900. In the library it powers 10 [Constellation](/brands/omega/constellation) references at 39 mm, 6 [Aqua Terras](/brands/omega/aqua-terra), 5 [Seamaster Diver 300Ms](/brands/omega/seamaster-diver-300m) in gold at 42 mm, 2 [De Villes](/brands/omega/de-ville), 2 [Planet Oceans](/brands/omega/seamaster-planet-ocean) and one Seamaster 1948. Cases run from 34 mm to 42 mm.

25 other watches in the library run the Omega 8801.

Omega

Seamaster Aqua Terra 150M Master Chronometer 34 Sedna Gold / Diamond / MOP / Bracelet

220.55.34.20.55.001 · 34 mm

Omega

Seamaster Diver 300M Master Co-Axial 42 Moonshine Gold / Black / Rubber

210.62.42.20.01.003 · 42 mm

Omega

Seamaster Diver 300M Master Co-Axial 42 Sedna Gold / Blue / Rubber

210.62.42.20.03.001 · 42 mm

Omega

Seamaster Diver 300M Master Co-Axial 42 Moonshine Gold / Green / Rubber

210.62.42.20.10.001 · 42 mm