Welcome aboad Frau Phillips (maybe that should be Fraulein until you are married?).
I know exactly what you're talking about here, as my wife (Maxine) has been through the same thing (both with submarines and aeroplanes), I've dragged her on board U-534 for a tour, forced her to fly in 1930s biplanes with me, made her sit there with me watching war films ('Has this one got blood and snot in it too?' is her usual comment) and basically dragged her all around the country to look at rusty old boats and aeroplanes!
But I don't get away with it all for free, her hobby/interest is breeding dogs, which means I get to live in a house with eight of the things (just one doggy being mine). I also get dragged around the country with her to go to various dog shows (which often bores me to tears, I have to say), but our marriage is a two-way street where sharing each other's interests is something we (occasionally grudgingly) do.
My wife is now very knowledgable about WW2 aeroplanes and submarines, and can spot a Spitfire further away than the average Luftwaffe pilot probably could. And one of her friends was actually in The Dambusters movie. Similarly, I know more about the genetics of dogs than I ever really wanted to (I prefer throwing frisbees for them in the park), and I can actually groom and trim a dog properly for Crufts.
Sharing an interest with someone you care about is one of the bits of mortar that cements a relationship together. So good luck to the pair of you.
Incidentally, my wife thought that the Das Boot plays Silent Hunter clips were hilarious.
Chock