SeaHound - I'm married 33 years. First 25 years of it (when we could manage a vacation), we'd go someplace where my spouse would: bike, hike, fish, ski, kite surf...blah, blah, blah and I would sit around, read, twiddle my thumbs, drink fruity frozen cocktails and wait for him to finish whatever activity he was involved with so we could have dinner together.
Then one day I told him (for a variety of reasons) that I wanted to run away from my life and he asked, "What will you do with your life if you run away? Can you name just one thing that you might find appealing?" For some reason, the first thing that came to mind was "I think scuba diving sounds like an interesting pursuit."
One week later I came home and found a big black equipment bag (with a big red ribbon and bow around it) containing a mask, snorkel, fins, wetsuit and a certificate for the PADI open water certification course. There was a note that said, "And now, you have to take the class because it's already paid for and non-refundable."
That was 8 years ago and now I'm a divemaster. Nice story, huh? But to answer your question, my spouse (who will do anything BUT scuba dive because he has ear problems, feels claustrophobic and finds the whole underwater experience anxiety provoking) has no problem with my taking solo dive trips several times a year.
I think leaving a spouse behind can be a very hard thing to negotiate in the early years of marriage and separate vacations can raise a few eyebrows, but healthy relationships can and should reasonably sustain the freedom of partners to pursue individual interests. The 2 key words here are "negotiate" and "reasonable". Good luck.
