About eight years ago, we had the same thought, though we knew almost nothing of boating and ownership, other than we had fun when we went out on some friends' boats. With some friends of ours (a family of four with similarly-aged children), we went looking for a family boat that would handle at least 10 people, have plenty of space for everyone to relax, and be capable of towing various water toys for the kids.
Our plan was to buy the boat together, and split the expenses 50-50. After much searching, this is what we wound up with…
That's a 2002 Maxum 2400SD, a 24-foot-long (more like 27 with the swim platform) family cruiser of a boat. Although old in calendar years, the boat had a brand new engine, and appeared to be in good shape. (Maxum was a Brunswick brand; they also own Sea Ray. Brunswick discontinued the Maxum line in 2009.)
One of the things we had trouble finding before we bought our boat was information on actual real-world costs: Just how much money will you spend not just to buy, but to use and maintain a power boat? To help others who may have similar questions, I'm going to share our actual costs from seven years with our boat. If you're thinking of getting into boating, perhaps some of this cost information may be useful.