Hello mattyboy and all of you,
my opinion is that you should not give up a hobby for a woman.
There are many interesting and different things for both of you to discover during shipspotting. Explain to her some details of the ships you are watching and she will eventually build up a knowledge about ships and shipping. There are so many benefits for both of you to enjoy while watching the ships passing by : Nature, a great scenery, fascinating animals can be seen (my wife and I are keen birdwatchers, so this is really a good additional motivation), wonderful fresh air, sunshine and many other things. You can enjoy taking your meals at very special places having a great panorama at the same time.
Perhaps the woman you have met, mattyboy, will be inspired and "infected" by all these great experiences ? It should work if you are skillful and patient. And what about making a nice ship journey with her or some harbour trips ? And perhaps she is or gets interested in photography and takes photos by herself ? There are a lot of other subjects that can be seen during a shipspotting tour or on the way to and from these locations.
Last but not least it is very important, in my opinion, that you should try to visit a great variety of shipspotting locations if possible, so this should never become boring to her.
Perhaps try it this way, good luck and best wishes to all of you from Hans