Hard to see things from this photo alone, but here’s what I think I see: Dive watch, -or at least dive style-, black dial, huge triangular lumed indices, also I think I see a big lumed hour hand. Unfortunately there is a huge number of such watches from many makers, they were very popular at the time. Some were very cheap with plated cases and pin-lever movements, some were proper, steel dive watches. Here’s one example, from the more “affordable” side :
Agree with you here. Definitely an old skin diver type watch, my guess would be a Saxony or Sheffield All Sport. I was thinking Sheffield in my head and this came up with my search and it’s from the same company.
Thank you! This certainly looks like the right kind of thing and I know the image isn’t much to go on.
If it helps at all, Dad was a great believer in Army/Navy surplus kit and often bought yachting supplies from the gigantic ramshackle stores that flogged off old military equipment from the immediate post-WW2 period. I have no specific reason to believe that this watch may have come from such a store, but it would fit with his character!