It's been OP's watch since purchase in 1960.
@Tim.Cree: it does seem like a 2846, and it looks in great shape. At some point you must've had it serviced, and the original clover-leaf crown was replaced. There are hundreds of variants of this reference, but they're lovely watches, powered by the Omega cal 500, which IMO is a great movement that is as good as any being made at the time. The dial seems not to have been redone, and still has its original font, which is especially good looking on what's called the coat-hanger S on Seamasters (how the bottom part of the S goes sort of aggressively far down). Anyway: it's a really lovely watch. Must've been fun to have for 60 years now; I'm sure you+it have seen some great adventures.
