The concept of timeshare has a history in the marine community that is questionable, at best. Traditionally, people who do not own boats but who want to use them for periodic vacations will charter them, or rent them, for a week or two at a time. Everything from a 30-foot sailboat to a 300-foot megayacht can be chartered, with prices ranging from less than $4,000 a week for a bareboat that you sail yourself to upward of $400,000 a week for a fully crewed luxury vessel.

The boats typically are found in the Caribbean and Mediterranean seas, though some are also available seasonally in places like New England, Alaska, the Chesapeake Bay, Florida, and the Bahamas. There are a few floating around for charter in Scandinavia, the South Pacific, and beyond, but because boats require provisioning and other shore-based services that can be very expensive in remote locations, they tend to be available for charters only in destinations where the broader masses of people typically like to vacation.

Sounds a lot like hotel rooms, right? And since timeshares are succeeding as an alternative to buying hotel rooms all over the world, then wouldn't timeshare use of boats be a logical extension of the boat-charter market, too? You would think so — unless you knew a little bit about how boat charter works.

People who charter boats like to go from Point A to Point B, sailing where the wind and their imaginations take them. That's a lot different than returning to, say, the same vacation resort on the same stretch of beach year after year after year. If you want to sail from St. Martin to Antigua, for instance, but the guy who plans to be aboard the boat the week before you wants to sail from Tortola to St. Thomas, you are going to have a logistics problem. Hence the concern with offering boating timeshares. The people who own the boats do not want to have to pay the extra repositioning fees to get the boat from where the previous guy wanted it to where you want it. And so instead of offering timeshare usage plans — where you would have a say in where and when you get to go — the boats offer one-time charters, allowing them to take or turn down your vacation requests just the same way hotels do.

It is for this reason that timeshare has had such a hard time gaining a foothold in the boating industry. And yet there are a few companies trying a version of it that would seem to make sense for some types of boating vacations in the future: more-or-less fixed itinerary fractional ownership plans in which you start out and end up at the same base marina year after year after year, but you can sail wherever you want to during your annual week of boat usage.

The company Elite Island Yachts — a division of Festiva Resorts — is one firm that is trying this concept out in partnership with The Catamaran Company, a well-respected boating company that has been in the charter business for years. Elite Island Yachts will have a fleet of Lagoon 440s (which are 44-foot catamarans with four cabins apiece) based in Tortola, St. Martin, and St. Vincent, three distinct Caribbean cruising areas. You, the timeshare owner, will pay a onetime fee that will let you charter out of any of these home bases for a total of twelve to thirty-six weeks during the course of your twelve-year membership. You can use the Lagoon 440 on your own and act as the captain, or you can use three of the staterooms for yourself and hire a captain (through the company) to stay in the fourth cabin and take care of business along the way.

You cannot sail between the home-base destinations, as you might on a cruise ship, because they are simply too far apart for a smaller boat like a 44-footer to reach in a week's time. But you could alternate among the vacation destinations in much the same way that you would alternate among an exchange company's resorts — only without having to pay the per-vacation exchange fee on top of your cost of membership.

For more information about this timeshare opportunity on the water, go to www.thecatamarancompany.com. You also can look for additional companies' promotions in the top marine-industry magazines, such as Power & Motoryacht (www.powerandmotoryacht.com), Voyaging (www.voyagingonline.com), and SAIL magazine (www.sailmag.com).