I have to disagree that a sailboat is not a good investment. You just have to have a good eye to find a bargain boat that is a bit of a diamond in the rough. I will give you three examples of good investments from my own experience:
My first boat I bought on my own (not one of my dad's) was a Catalina 25 that I bought to cheer up my dad when he sold his big 35 footer due to cancer. It was a 1985 model that looked cosmetically bad, but was structurally sound, had a roller furling, intact sails & a working outboard & worn trailer. I spent about about $1,200 to purchase her from a boat museum donation. I spent about a grand to fix her leaking swing keel trunk, & spent about a month or two to clean her up, new cushions, bottom paint etc. I sold her for $7,500 a year later. That was a profit of about $5,000. Not bad - more then doubled my money.
2. My second investment boat was a 1980 28 foot S 2. These are well known for being very solid & well built sailboats. She looked neglected & had a coral reef growing on her bottom. But she had good North sails, roller furling, & a working Yanmar diesel & wheel steering. Got her seller down to $5,000 cash for her, a steal. Hauled her out & spent about a grand for a new epoxy barrier coat , bottom job & cleaned her up good. A good wax job can make a tired boat look new again. Enjoyed sailing her for a year, and put her on the market & sold her for $14,000, the full value of the boat in good shape. That was a profit of $8,000!
I felt pretty good after that sale, & immediately was on the hunt for next, bigger cruiser for myself & my growing family.
3. My current boat is a 1980 Catalina 30. Took the 8-9 k of profit from the S 2 sale & bought the C 30 after talking the buyer down form 12k. She also has the assets that I always look for in a older sailboat: structurally sound, solid decks. Useable sails, roller furling, wheel steering and a working diesel engine. Dirty boats with dated aesthetics are the ticket to dropping the price. But if you have to replace sails, rebuild engines or do major structural repair then it isn't worth it. By a boat that is in sailable condition but needs some TLC & talk them down on the price. Cash money talks. Start waving around several thousand dollars in $100 bills, & I guarantee that the price will come down to your budget. The C 30 I bought is worth nearly 20 k in her current excellent condition. I have about 11k in potential profit /equity in her. So with three boats I made a total profit / equity of around $24,000 bucks, part time & enjoyed the hell out of sailing & owning each boat (slip fees not included). Cheers.