Both watches do the job a dive watch is asked to do in 2026, which is almost never diving. What separates them is proportion and price: 39 mm against 42 mm, and a gap of several thousand euros.
The Omega is the better-engineered object by any measurable standard. The Tudor is the one more people will actually wear every day, and that is the criterion we weight highest.
Tudor · ~$4,800Black Bay 58
OMEGA · ~$7,000Seamaster Diver 300MThree millimetres of diameter and 1.6 mm of height sound like nothing written down. On a 17 cm wrist they are the difference between a watch you forget you are wearing and one you adjust twice an hour. The 58 was designed backwards from the 1958 case, and it shows in the lug curve.
METAS certification tests the assembled watch, not the loose movement, and holds it to 0/+5 seconds through 15,000 gauss. COSC tests the movement alone to −2/+4. Omega's standard is the harder one to pass, and the co-axial escapement stretches the service interval to eight years.
Aluminium bezels fade and scratch; ceramic does not. Tudor's insert is the period-correct choice and will patina, which some buyers pay extra for elsewhere. Omega's ceramic with enamel numerals will look identical in fifteen years. Both positions are defensible; only one is objectively more durable.
The gap at retail narrows on the pre-owned market, where both hold well, and servicing narrows it slightly further over a decade. It does not close it. The Tudor is the cheaper watch to buy and the cheaper watch to keep.