If you want to understand the difference between Rolex and Omega, put them both on a wrist underwater. Both work. But they work differently.
The Submariner is the watch of reliability. It works because it is Rolex. It works because millions have worn it and all of them came back alive. Pre-owned Submariners in steel run £7,000 to £12,000.
The Seamaster is the watch of heritage. It flew with astronauts. It survived chemical spills in laboratories. It has a story. Pre-owned Seamasters run £3,000 to £7,000, depending on model.
Both are right. The Submariner if you want reliability as a given. The Seamaster if you want a watch with a history worth telling.
The choice that matters
Neither watch will fail you. The choice is about which company’s philosophy matches your own. That is all that matters.