Calculating sail area

The gunter rarely has the gaff parallel to the mast, though it's usually pretty close. Some rigs are very close to the gunter, but lack the details that separate it from the gaff. The Mirror is a classic example of this, being a gaff, though proportionally looking like a gunter. The gunter is a sliding lug.

 

I've always thought of a gunter rig as lacking a throat halyard, but that probably only applies to the smaller ones.

 

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No, it's a gaff, Gonzo.

 

Seeing the profile I have to agree it is a gaff

 

Gaff/Gunter

Found this on wikipedia and thought it was interesting:

Gaff vs Gunter Rig

Over time the two terms have been used with some interchangeability. While a true gaff rig is with the gaff at an angle to the mast, small boats such as the Heron, the Mirror dinghy, both designed by Jack Holt, and other small sailing dinghies have small, light gaffs which are raised to the vertical position by a single halyard fixed close to the midpoint of the gaff.

This looks like a gunter rig when the boat is fully rigged. However it does not have the sliding component of the wire or the hooped gunter.

Nonetheless such small dinghies have been termed 'gunter rigged' and 'gaff rigged' with free use of each term. It is likely that the fluidity of language allows both terms to be used with correctness for these small boats. For larger craft the terms tend to be more rigorously applied.

 

Wikipedia nonsense yet again. The Mirror (et al) do have a sliding component.

 

If the upper spar is parallel to the mast then presumably the only benefit of a gunter rig is a shorter mast? Is that so?

 

Roughly speaking the gunter rig on smallish dinghies provided most of the advantages of a fractional bermudan rig, but with spars that could be stored within the boat. In the 1930s - 1950s there also seems to have been a belief that two shorter spars, typically solid, would be cheaper than one longer spar, which was typically made hollow.

 

The gunter was used in smaller craft to keep the spars within boat length, while still offering a jib headed mainsail shape. They work fairly well, but as sizes go up, the really lousy gaff purchase, could prevent the typically long gaff, from falling off badly. Friction was another issue in larger sizes and they tended to jam when you needed them to come down or have more control, at the most inconvenient times (reefing, building winds, etc.). In really small mainsails, a single halyard on a balanced bridle was common, though once over about 80 sq. ft. (natural fabrics) or 120 sq. ft. (dacron), you'd need a typical throat/peak halyard arrangement.