Yep. unless you can prove you paid sales tax in another state Washington will make you pay sales tax on recreational vehicles (boats, motrocycles, etc) when you bring them in state. And even if you paid sales tax in another state, if it is lower than WA, you'll have to pay the difference.

Thankfully, when I moved here ~10 years ago I had saved my sales reciept for the motorcycle I'd bought years before in Texas and only had to pay the ~2% difference.

Some guy I used worked with moved here from Michigan and had a ~$40,000 sailboat he'd bought there years before. He couldn't produce the original sales receipt, so WA wanted him to pay sales tax again on the whole amount in order to get it registered. He ended up having to sell it as he couldn't afford to pay the tax and didn't want to pay moorage on a boat he couldn't use .