I'm going to go against the majority of posters here and tell you that I don't see anything wrong with a boat loan, but with a little additional advice as to how to go about it. While I'm still regarded as a "Newbie" on this forum, I have been around the block quite a few times, and I have financed three different boats over the years.
My advice is to first take a long hard look at your finances, both today, and in the near term future. If you've already got a secure job, you're into a home that you plan on keeping, and all of your other existing debts are under control, you should know what you can comfortably control. The two best people to help you with this thought process is your banker, and your spouse. Make sure to take the advice they both give you, for obvious reasons.
Once you've figured out how much you can afford, don't make the mistake of rushing right off to the new boat store. While you won't end up with the absolute latest and greatest, the used boat market is normally the better option. Let the first owner take the big depreciation hit for the first couple of years.
And make sure to keep the length of any loan down to around 3 - 4 years. This faster payoff will give you the chance to build equity in your boat so you can always trade up every few years or so while keeping roughly the same payment. Taking out a 10+ year boat payment will only leave you with a paid off boat that will be worth about what the old payment book is worth.
Hey, being debt free is great, I've been there since 2003. But there is nothing wrong with well managed debt, as long as it is well managed and you don't end upside-down a year or so down the road.
BTW - Right now, I've down sized from a 19' Pantera II with a $200 per/month payment, into a 17' Lund without a payment.