With all due respect, I personally think the "you should NEVER finance boats, etc. etc." statements are asinine. One thing to keep in mind is everybody's situation is different, but most of the time it is smarter to finance due to opportunity cost. Granted, you have to have self-discipline but we are all adults here. I had a well kept 1996 skeeter zx200 until last November when I found a killer deal on a brand new, model year clearance FX20. I'm blessed to be self-employed and have the money to pay cash for it, but I would be feeling pretty broke if I did. I chose not to pay cash for it and here is why: I could finance through my local credit union for 3.9%. This means over the next 5 years(if I don't pay it off early) I will pay an extra $4,800 in interest. So I put a decent down payment on it so that I could sell the boat fast and get more than payoff for it if I ever got in that big of a bind. Then, I took a portion of the money I would've sent the dealer if I paid cash and I invested it. My first payment was in December, so I have made 4 payments so far and the small portion I have invested has made over $1150 in that same amount of time. I've already made over 1 year's interest in just 4 months by investing the money. Why save money if you aren't going to put it to work making more money for you?

You can only tell your story this way because the market has been climbing in the timeframe of your anecdotal example. On average, the market goes DOWN about as much as it goes up. Part of that "up" is gradual inflation creep as well, so it's not as much profit as might appear. Don't get me wrong, I've been fond of wise investing and it has served me well, but your particular story at this particular time in finance history is because of circumstances. It can be opposite of what you say just as often.

Since you are touting the investing benefits of taking out a loan, I'll offer another scenario entailing investments. How about the benefits of compounding? Try that INSTEAD of financing, and decent savings/investments can yield the total amount needed to buy the boat with no loan. Once you have the boat, some of the funds previously earmarked monthly for the boat fund could be diverted to operational expenses such as gas, insurance, etc.

Unless you make your living with a boat, financing one will never make fiduciary sense. People finance them because they want it NOW and they want it bad enough to PAY. Some even do it when they really can't afford it - they just convince themselves they can until the day they have no choice but to unload it.

I really am not trying to argue and I respect whatever way you wish to afford your boat, however I think it is fair for the person asking the question to see both sides. I am not only talking about the stock market, I am invested many more ways than just the stock market. But there can also be money made on the downfalls of the market, actually the $1150 I have made with my $5,500 investment has been primarily short-selling during this "time of climbing markets". I'm working against the market and making money. It's been done on the downfalls as well though not as often. Don't get me wrong, do I think it is good to be able to pay cash, yes I do. However, as I said I could pay csh but chose not to because I also think most of the time you're costing yourself money. As you said, unless you fish professionally that 65k you spend on the boat isn't going to make you a dime. But when invested, that 65k can pay for part of your boat, and you'll be essentially paying less for the boat and getting it sooner. You can literally have your cake and eat it too. I agree compounding can be great for retirements and other long term goals, being self-employed that's actually one of the ways I am preparing for retirement. I personally wouldn't buy a boat that way, but to each their own.
Here's the deal though, if a person invests $10,000 it will take 20 years at 10%(unlikely) annually to have $67,000, just about enough for the new boats many people buy. Most people don't start at my age, but even I would be over 40 if I started today. Why wait that long? Beyond playing the markets there are so many other $10,000 investments that have decent chances of making way over 10% a year and being re-invested or being sold if you need the money. The fact of the matter is it's a balance of risk and reward. Maybe it is because I am young and have a lot of time to make money to retire with, or maybe I'm senseless but I personally would much rather be a little bit riskier than accept minimal rewards. 20 years to make $57,000 is $2,850 a year on average.... I own about $10,000 worth of equipment that makes me way more than $2,850 a year and somebody else is running it, that's an investment. My example is far from anecdotal, while it is my personal testimony that money can be made with wise investments, it's a proven fact just the same, it's in every finance and economic textbook and every economists will agree that money can be made investing. Go tell any billionaire that success while investing in the stock market or even in tangible items is anecdotal and you'll be laughed out of the room. People make money with investments all the time. If your goal is to save up for 20 years just to buy a boat then I hope you succeed or have succeeded, but I personally have bigger aspirations than just being able to buy a boat in the next 20 years and that's why I have chose to do it the way I am. Like I said, even if I lost my work and my stock market investments bottom out, I can sell the boat and more than pay it off, or I can sell part of my tangible investments to pay the boat off. That's the beauty of not having every dime tied up in paying cash for a boat, I have a boat and other things as well that actually make money and are valuable if sold. Like I said earlier, literally having your cake and eating it too.
I also like to think of it like my friends at college who have student loans. Some of them up to 200k through med school. Would you tell them not to take out a loan for college, that they should go to work and start compounding until they can afford to go to college in 20, 30 or even 40 years? No, most people say college is an investment because it will make you money in the long run. That's no different than financing something you have the cash to pay for so you can invest that cash you have in something to make money. Except the investments I made with my "boat fund" are making money now, as to where student loans won't make money for years and years. And just like the stock market can fall, the need for petroleum engineers who have 100k in student loans can fall too. What's the difference?