I have a strong preference for conventional rigs (slap-reefing) with a good slide system, triple reefing setup, and lazy jacks or the Dutchman system for ease of dropping sails. This is a relatively simple, time-tested system that requires a bit more work for the crew but it has its advantages: better sail shape (performance), full-batten capability, less weight aloft, and ultimately, better reliability. If in-mast furlers (IMFs) jam, it is likely to happen at an inopportune time. I am not a fan of IMFs for this reason. Nevertheless, the conventional versus the IMF rig debate rages on.

Now to IMFs… many (say over 50%) of new monohull cruising boats over 40 feet now are built with IMF systems and this includes premium "blue water" boats - Oyster, Halberg-Rassey, Hylas, and Amel to name just a few. Production boats such as Hunter, Beneteau, and Catalina use them. Charter fleets which use many of these production vessels in their fleets use them extensively.  Most of the charter boats in the East Med use them.

The greatest attribute of IMF is it tends to make for lazy and poor sailors to stow the sail and turn the motor on. Given that many charterers are usually not the most experienced sailors, today’s IMF systems must be reasonably robust and reliable. If they were not, it is hard to imaging all the charter companies spending money on sail and IMF repair/maintenance. IMF systems did come a long way in reliability and performance…for example, the newer Selden IMFs are better than systems from the late 80s to early 90s.

Many owners of newer IMF systems are satisfied and will accept the sail shape and performance issues as a tradeoff for easier sail handling and stowage. IMFs do require more care during the furling to avoid possible jams in the furler system. The variables are angle to the wind, halyard tension, boom position, and furling line tension.

Many of these IMF system sailors are not long-term cruisers. Those in the charter business and weekend sailors tend to use their vessels in relatively good weather when conditions are mild. For weekend sailors, I believe that IMFs serve their purpose and seem to be a popular feature on new sailboats.

Although I never experienced it personally, I believe that long term IMF cruisers will sooner or later be faced with some type of issue or jam while underway in moderate or heavy weather. These situations may tend to occur while underway in a reefed situation or in strong winds. A jam under this scenario leaves ugly options as one cannot drop the main if it is reefed in at all. Often a possible solution is to wrap the mainsail manually around the mast and lash it to the mast, a difficult task in 30+ knots of wind. I have seen several vessels with jammed IMFs during my cruises returning to port with their sails wrapped around the mast.

What about jib furlers? I am a proponent of jib furlers because they have also come a long way in terms of reliability. With jib furlers, I am willing to accept the downsides of possible jams and sail shape issues when reefed as they are more easily fixable.

For those cruisers that must have a mainsail furling system, I would recommend an in-boom system, such as, those made by Schaefer and LeisureFurl. Furling booms do jam as well, but the sail can be dropped to deck a lot easier. Of course, there is the issue of cost.

For longer term cruising situations, I prefer the tried-and-proven method of slab reefing with a good batten car system and lazy jacks. With single line reefing I can make a reef as quick as IMF sailors. And, if all else fails, can easily drop the main. Of course, if one wants to be spoiled a bit, just install an electric halyard winch.