Duckworks - Projects
The Online Magazine For Amateur Boat Builders

Sliding Gunter Rig
By Chris Wentz drawings by the author
from Small Boat Journal #42 May. 1985

At first glance, the sliding gunter rig would appear to be the ideal rig for small craft. It sports a profile very similar to the popular Bermuda or Marconi rig, yet its spars may be shorter for the sail area spread than any other rig with a triangular sail. This rig saw much development at the turn of the century, when interest in small cruising vessels resulted in some wonderful canoe yachts that still stand as works of marine art. But today the gunter rig is mostly seen in dinghies, where it offers the possibility of an efficient sail with spars short enough to stow entirely inside the boat. In some respects, the gunter rig compares favorably with its cousin the Bermuda rig, but it has inadequacies that have rightfully kept it from being widely popular.

The principal liability of the rig is the yard, the spar that extends the luff of the sail above the masthead (Yes, it's called a yard despite its resemblance to a gaff). Like a gaff, the pressures of the wind on the sail make the yard tend to twist off to leeward with a consequent loss of efficiency. Ideally, the yard would he firmly fixed against the mast, as though held by a splint. The problem is to design a joint that sets rigidly, yet may be lowered away instantly.

Some wonderful schemes have been concocted to set the yard properly. Generally, the heel of the yard is fixed to a slide, and the halyard holds the upper part of the yard to the masthead. The halyard also guides the yard into a clip that seats the yard and holds it fast when the halyard is belayed. The trick is to make the clip strong enough to withstand a bashing from a recalcitrant yard, without it being unduly clumsy, heavy, or complicated.

Saggy Yards

As clever as the rigging methods may be, one drawback of the gunter rig has defied satisfactory solution: making the yard stand properly with a reefed sail. When sail is reduced, the yard sets at a lower postion, and the halyard's attachment point on the yard moves away from the halyard sheave. As a result, the halyard can't accurately guide the yard into the clip, and the yard sags off. The more deeply the sail is reefed, the worse it sets. One could move the halyard's attachment higher up the yard, but reefing down a small boat in a breeze usually gives one enough to do without having to re-rig the boat as well.

In addition to the gunter rig's reefing problems and its need for special fittings, many sailmakers simply have trouble cutting a sail to Fit the gunter. They seem lo think that the luff of the sail must hug the spars very closely. As a result, the throat of most gunter sails tuck in right under the base of the yard to join the mast immediately. Unfortunately sharp lucks and cut-ins in the luff of a sail do not benefit its shape. Better to simply fair the luff back to meet the throat.

Since the result is a nice efficient leg-o-mutton sail, all of this trouble might be worthwhile. But sprit or lug rigs using short spars can easily spread half again the sail area, thereby boosting performance greatly despite their reduced efficiency. Furthermore, sprits and lugs don't require special fittings or tricky sail making, and if all that sail gets to be a bit much, they reef perfectly.

Efficient Sail

Despite its drawbacks, the gunter rig was once popular on small cruising yachts, some of which did extensive coastwise sailing. The designers of those craft did their best to accentuate the positive and eliminate the negative. They used two-masted rigs and designed their vessels to balance well in a breeze under jib and mizzen only. This is when the benefit of the short mainmast is fully enjoyed. With minimal unwanted windage and a low center of gravity, this is a very good heavy weather rig indeed, especially for small craft that by nature
aren't terribly stiff.

If a breezy passage is expected, a trysail can be set on the mainmast without the yard. These sails aren't great performers, being short of luff length for their area, but if it really starts to blow, a wee ship with gunter rig can heave to under the trysail very nicely. Or, depending on how much sea room one has, she can lie head to wind with just her mizzen and a sea anchor.

The sliding gunter rig is ideally suited to small craft on which a triangular sail plan is desired, in which all spars must be easily stowed, and aboard which a skipper must be able to set and strike the rig. If you always sail in pleasant weather, and avoid having to reef, so
much the better.

Chris Wentz is a founder of Z Sails