RV vs Boat: What’s The Better Family Investment?

My fiance and I are daydreaming... We're hoping by the end of next year to buy either a boat or an RV/Trailer (Extremely cheap, extremely used I might add, we're not ballers). In Idaho and the PNW, what's the better investment? I say boat, she says RV.

Now, I've always wanted a boat. I love the idea of lake days and swimming and splashing around and slingin' the kids off the inner tubes, all that. But, it's fairly limited in terms of what you can do with a boat. I mean, you can go in the water. That has a lot of great things that come with it but basically that's it.

She wants an RV or a trailer (we have a Silverado 1500 already for context) that we could tow around the region, and we're still pretty new here so there's obviously LOTS to see; plenty of different camp sites, etc. So for travel, that's obviously the better choice. For fun, boating is obviously the better choice.

So, say you had 10 grand to work with, what would you do?