Dear Boat Doctor,

I need a new genoa furler on my Passport 40 and I am not sure where to start. I have looked through a couple catalogs and they seem to be sized to the length of the boat, but it feels like I need to know more. Can you help?

Lou Brooks

Providence, Rhode Island

Dear Lou,

Roller furlers have gone from blasphemy in the 1980s, to convenient and downright essential cruising gear. You need a furler you can use and trust in any condition and on any point of sail. I can definitely help you pick the right one.

Let’s start with size. Furlers are specified by the clevis pin size and the length overall from deck to masthead. A given furler model will list the pins it supports (typically two) and the maximum pin-to-pin length it can support. For example, a Harken MKIV Unit 3 will support a ¾-inch or 7/8-inch clevis pin and a maximum length of 81.6 feet. A Harken MKIV Unit 2 will support a 5/8-inch or ¾-inch pin and has a max length of 67.25 feet.

The pin size and max length are hard specifications. The pins must fit and you can’t go over the max length, but, you often have options. Say your boat has ¾-inch clevis pins and a 65-foot stay length? You could chose the Unit 2 or Unit 3, but in nearly every case you will be better off with the bigger furler. The larger drum will offer more furling leverage and the bearings will be beefier giving more load carrying capacity. That bigger furler will cost you another $1,000, but you’ll thank me on that squally day when you furled with ease. The only time a bigger furler is a bad idea is if it won’t fit. For example, if you have a very tight bow pulpit that the larger drum physically won’t fit inside.

With size out of the way, let’s talk design features. Modern furlers are all built pretty well but manufacturers make different design choices. Open bearings versus sealed, bearing materials, round versus elliptical foil sections are just some of the factors to consider. There are pros and cons to each, with no clear winner, in my opinion. I see the leaders in the market as Harken, ProFurl, Selden/Furlex and Schaefer. Pick your favorite and get the bigger model if there is an option.

When you install a new furler, pay attention to your furling line lead, as a poor lead can make any furler unusable. You want to exit the drum perpendicular to the stay and lead cleanly to a winch. A winch is required to furl in a big sail in a breeze, just pay attention while you’re doing it.