My wife (No. 3) loves being out on the sea especially if we leave the three kids back on the beach after a family fishing trip.
She doesn't like the REALLY rough stuff but I think that's because she doesn't really have the confidence of driving boats a lot although is happy to tow me on skis until my arms drop off when it's calm.
Enjoys the fishing & didn't moan too much when we did a 25mile run last year down the Mull of Kintyre and is happy to chip in 50% of the fuel costs for the boat when we're on holiday !!
I would never discuss the cost of my 'cheap' hobby with her though, I might get a very long look.........