Offshore Log:Life with the Profurl

While Calypso's new furler is working well, there have been some quirks to overcome.


Our headsail reefing system, anchored by a Profurl C42 furler, has had its share of teething problems, most of which are associated with our particular installation rather than with the system itself. We have been plagued with very high furling line loads, so high that it takes either two people on the line in high winds, or requires taking the line to a winch to get it started.

The source of these problems is twofold. First, the position of the system’s upper swivel relative to the wrapstop is critical. Profurl points this out in the installation manual, but just how important it is was not apparent to us until we traced part of the furling load problems to improper alignment of the upper swivel, its linkplate, and the wrapstop. Due to peculiarities of our masthead design (there is a lot of offset between the halyard sheave and the headstay) we cannot correct this without removing the headstay and disassembling the entire system to alter the total length of the headfoil.

Our furling line is led through a total of seven blocks attached to the stanchions. Six of these are Schaefer 506-44 Clear Step blocks, and the seventh is a Schaefer 300-35 pulpit mount block. Individually, these ball bearing blocks are very low in friction, but seven sheaves inevitably increase the total furling effort required.

Finally, the furling line runs through a Lewmar 2910-1012 Superlock rope clutch. This clutch, too, adds to furling line friction.

The Superlock clutch holds extremely well, with absolutely no slip. Bleeding tension off a highly loaded furling line, however, requires a deft touch. The clutch holds until it releases suddenly, so that gradual bleeding necessitates a series of short releases, rather than a single steady ease.

For now, the final lead of the furling line is through the clutch to a snatch block which serves as a turning block, then back to the starboard primary winch. This works fine with the boat on starboard tack, but on port tack, the genoa sheet must be cross-sheeted to the port primary-not an easy task-in order to use the starboard primary for reefing. In the long run, we will have to add secondary winches-which we had originally intended, but had hoped to avoid since the back end of the boat is pretty cluttered with hardware. The secondary winches will also simplify spinnaker handling, and can also be used to tension the running backstays in situations where their four-part self-contained tackle proves inadequate.

We have also experienced some problem with the furling line jamming on itself on the furling drum. We have sailed with a reefed genoa in very high winds-30 to 40 knots, hard on the wind-where the furling line loads get very high. The current furling line is conventional 3/8″ polyester double braid, which is quite soft. When highly loaded, it tends to pull into the line already furled on the drum, greatly increasing the amount of load that must be applied to the furling line to reef the sail further. Part of the solution is to keep the furling line very tightly wrapped on the drum as the sail is unfurled. We now do this by tensioning the genoa sheet, easing off only 2 feet of furling line, re-trimming the genoa sheet, easing 2 more feet of furling line, and repeating this until the right amount of sail is out. It’s slow, but we aren’t racing this boat, after all.

In addition, when we do our major re-work of the furling system this summer, we will switch to a hard-lay furling line which should distort less when loaded.

Finally, our Profurl is an older model, with four separate furling line guide arms at the furling drum. On newer models, this arrangement has been altered by adding a continuous stainless steel ring welded to the top of these arms. We discovered just how important this change is when on one occasion the last two turns of the furling line were forced out of the drum past the guide arm. The line had bunched on the drum from my failing to keep adequate tension on the line as the sail was unfurled too quickly in high winds.

These last two turns wrapped around the lower part of the headstay. We were sailing between Carriacou and Grenada, and the wind suddenly increased from 18 knots to more than 30. When we tried to reef the sail, it was no go. Crawling forward, up to my waist in green water when the bow pitched under (we were close reaching at 8-1/2 knots, which was exhilarating but hardly rational at the time) I discovered the problem.

With another one of our friend Murphy’s laws in full force, the line that easily popped out of the drum went back in with a lot of difficulty.

If you have an older model Profurl with this guide arm setup, you should immediately retrofit the newer-style arm arrangement. We are obviously not the first people this has happened to, and we see a lot of older-style Profurls on cruising boats. Changing over will require removing the headstay at the deck and partial disassembly of the system, but we consider this a potentially critical safety consideration.

Interestingly, the problems that we have experienced are the very ones that Profurl addresses in their troubleshooting guide. Profurl’s installation and operation manual is excellent, as long as the occasionally free translation from French into English doesn’t catch you off guard.

With the exception of the older style guide arms-a design flaw which has been corrected by the manufacturer on newer models-our difficulties with the Profurl are either installation errors on our part or a function of the operational learning curve. After about 3,000 miles of blue-water sailing in Calypso, we’re still learning how things work.