Rita,

A in mast furling sail can make some boats look a little better. That does not outweigh the risk of catastrophic failure on a lightly crewed or inexperienced crewed charter boat. There are just too many ways that a in mast solution can end up jammed or inoperable to the point where only someone hoisted up the mast can cut the main off the mast. Point two there is no way to put battens on a furling sail and the sail must be made differently to allow reliable furling. The result all in mast furling mainsail poorly. There are very good reasons you do not find them on The Moorings boats.

They do make some boats look better and they do appear to offer greater control at times until the moment you lose all control with no one skilled to scale the mast and cut the beast down. the only prudent charter solution is the common lazy jack rig where anyone can simply release the halyard and the main will work its own way down.

Even the best crews can experience a failure out of sight inside that mast or find a sail that has changed shape enough that it will suddenly no longer enter the mast. If it is blowing that day. Then what?

If you simple must have furling then in boom is the way to go. Releasing the halyard will still get the main down when disaster strikes and you can still use a full proper sail with battens.

Sorry for the unsolicited dribble.