Are Roller Reefing Mainsails Worth Having?

Take a look at any modern cruising boat and the odds are it'll have a roller reefing system on the forestay. Some may have two; one for a lightweight genoa and another just astern of it for a working jib. If the boat is cutter rigged, then it's likely the staysail will be set on a roller furling gear too.

Not so long ago, we cruisers were quite content with these roller furling gears on our headsails and simple slab reefing for our mainsails.

Not, it seems, any more...

Most spar makers offer roller reefing mainsails  as an option to their standard masts and booms, and some are markedly more successful than others.

With headsail roller reefing systems, it doesn't matter too much if you've been a bit sloppy rolling a reef in. Perhaps the sheet was a little slack and the sail was flapping around. OK, it won't look very pretty and the sail shape will be awful, but at least it's in - and you can pull it back out and start again.

But not necessarily so with roller reefing mainsails, which are contained (and that's the problem) either within the mast or within the boom.

In-Mast Roller Reefing Mainsail Systems

in-mast roller reefing system for mainsails

At best, this is a quick and easy way - providing you get the procedure right - to reduce the area of the mainsail in a rising wind.

But it can go wrong; and if it does with the sail jammed in the mast groove you won't be able to get it in, out, up, down or do anything much at all with it - short of a bosuns' chair and a sharp knife.

Sails used with this system are flat cut, have little or no roach - or even a negative roach - and if there are any battens at all, they'll be vertical.

Halyard tension is critical; too much and you'll have a job getting the first few turns in, and the boom has to be adjusted just right, so you'll need a rod kicker. If your sails are new or in good shape, then you've got a good chance of this system working at its best, but it your sails are past their first flush of youth, and maybe a little baggy then you could be in for an interesting time.

And there's a penalty to be paid in additional weight aloft as a result of the all the hardware inside the mast.

You may have guessed, I'm not a fan...

In-Boom Roller Reefing Systems

Sailboat boom furling systems use a fully battened mainsail and are conceptually more seaworthy than the in-mast type, because:

  • if the sail jams in the boom slot, it's still possible to ease the halyard and drop it.
  • a sail jammed in the boom slot will be much easier to sort it out than one halfway up the mast.
  • reefing the sail in the boom lowers the centre of gravity, unlike the in-mast system which leaves the weight of the sail aloft.

For successful operation the angle between the boom and the mast is critical. In some systems this is fixed by a rigid kicker, whilst others allow a degree of articulation and rely on a spring in the kicker to return the boom to its correct angle.

The double swivel arrangement found on headsail furlers is also incorporated in some in-boom systems, which flatten the main without reducing its area.

But why Bother?

Both in-boom and in-mast systems are mighty expensive, and far from risk-free unlike a slab reefing system with lazy jacks which is:~

  • Simple
  • Effective
  • reliable
  • cheap
  • and you can fix it if it breaks

Mainsail roller furling/reefing systems? I just don't get it.

But am I missing something? Yes you are, says Brian Mistrot, a fan of in-mast roller reefing mainsails...

You are here: Sailboat Cruising > Sailboat Rigging > Mainsail Roller Reefing Systems

New! Comments

Have your say about what you just read! Leave me a comment in the box below.

Recent Articles

  1. 30 ft Sailing Boat Moored on the Italian Riviera (Ready to go cruising!)

    Mar 16, 18 03:49 PM

    We are selling our perfectly formed 30 foot sloop, which is currently located on the Italian Riviera. We are Chris (Brit) and Rossella (Italian) from

    Read More

  2. FP Bahia 46 catamaran in top condition with a great inventory.

    Mar 16, 18 11:15 AM

    This privately owned Bahia has been meticulously prepared for long term live aboard world cruising. The rig is more generous than on most cruising cats,

    Read More

  3. Dufour 425 Grand Large

    Feb 23, 18 07:55 PM

    Newer Dufour in very good condition, well maintained, tons of spares and extras, 3 bedrooms with generous room, 3 bathrooms 2 electric flush heads w/showers,

    Read More