I think Sunchaser raises very important inssues in his post #23. If you count our use of our trailerable fishing boat as well as our diesel cruiser we have been boating in salt water in the PNW for close to 30 years now. While we enjoy boating in the fall, winter and spring, the majority of boat owners here don't. Our nearly 2000-boat harbor is nearly devoid of recreational boaters from the begining of October through April or May.
So the boating season is relativley short, partciulaly if boaters have school-age kids. Eight owners vying for boating time during a three or four month period could get frustrating.
Prior to deciding to buy our own cruising boat here, we chartered a similar boat. And while chartering can make a lot financial sense, particularly if one's boating is going to be confined to one vacation a year, it has definite drawbacks.
An option for the buyers of a newer boat is to put it into a charter fleet. While the owner generally never makes money with this sort of arrangement, putting one's boat in charter can often cover the annual ownership cost of a boat.
We never considered this, or a "condo" type boat ownership scheme for a couple of reasons. One is the time and schedule limitation it places on the owners. But the big one for us is that you can't set your boat up the way YOU want it. Like a charter customer, you have to schlep all your stuff off the boat when you leave it.
As I suspect is also the case with year-round frequent boat users on this forum like Art and FlyWright and Mark, one of the things we like best about boating besides the boating itself is the fact that we can set our boat up exactly the way WE want it. We can leave our foul weather gear in the hanging locker, my wife can have all her cooking doodads on board exactly where she wants them, we can keep all the books we want on board, from bird and plant identifers to navigation and cruising guides, we can hang the pictures we want, and on and on and on.
If we want to go up to the boat on any given weekend and just hang out because the weather's crappy or we don't have the time to take a longer run into the islands, we can do it on a moment's notice and we don't have to pack and drag a bunch of stuff with us and then take it all home again the next day.
We know people who have boats like ours in a charter fleet, and it's working very well for them. But they are not the kind of people who use a boat like we do. Their schedules and other committments only give them time to take a cruise once or twice a year.
So chartering one's boat, or buying into a "condo" boat or multiple partnership can certainly work, but its success depends entirely on what the owner or partners want out of their boating experience. It would never work for us, nor would it work, I suspect, for a boater like Art.
If the original poster will be time-limited in his use of a cruising boat and does not want the year-round demands a boat can make of its owner, then a partnership could be a good way to go.