A new ballot on the rig rule is immanent (honest!), essentially because nobody likes the current arrangement.
These days about the only defender of the 2-rig rule is its originator Roger Stollery. He detests forums and is unlikely to make his point here, so I think it would be in the general interest if I put the basic case for the rule as it stands.
First, there is a lot of surrounding hogwash about enhancing sailing skill, cost of rigs … You, the punters, do not seem to think that any of this makes sense, and that is an area in which you collectively are much more capable of giving a valid opinion than the rule makers. However, there remains a basic naval architectural justification for two rigs, one of a fixed maximum height. This is quite subtle and not widely understood. Before we commit ourselves, let us make sure we all understand just what the implications may be.
Suppose we have only one rig. In any given day there is a risk that we will be either underpowered (not enough sail) or overpowered (too much sail). This depends on the combination of the amount of sail area and the stability of the boat, which in turn depends on its beam and weight. Since the sail area is easy to change and the beam and weight of the boat are not, we will tailor our only rig (for the day, the race or just generally for the place where we sail) to minimise the risk of our being either underpowered or overpowered. In selecting a new design, we will go for a boat with lots of stability – wide and heavy, what I have lampooned in the past as the ‘muscle Footy’ – since this will extend the range across which we can carry a large sail area. Overall we will probably gain more on the swings (horsepower from a bigger rig) than we loose on the roundabouts (drag from the bigger hull), particularly over relatively small fluctuations of wind speed.
If we now increase the number of rigs to two, the picture changes. Each rig has its chance of being underpowered or overpowered. However, by getting the right balance between the sizes as the larger and smaller rigs right, we can greatly increase the likelihood of having the right amount of sail at any given time. However we can foul this up by biasing the larger rig excessively towards light airs and the smaller one to heavy airs. We will go brilliantly in calms and gales and either wallow or drift anywhere in between.
Now move the goal posts again. Set a maximum size for the smaller rig. This sets an absolute limit to the amount of heeling force we can generate in heavy winds (whatever they may be where we sail). Since the heeling force is limited, the amount of stability (= beam and weight) we can usefully use to hold the boat up is also limited. Since stability = drag, we want no more of it than we have actually need. The consequence is that stability is kept down by the fixed size of the small rig, which means in turn that the temptation to go for massively stable boats, perhaps in the style of a Balmain Bug, but without the swinging keel, is reduced. The two rig rule keeps (or is intended to keep) Footys as pleasant little boats of moderate displacement. Do away with it and you possibly open up the road to much, much heavier boats with massive sail plans because they are able to plug the gaps in the performance envelope by adding rigs.
There are other considerations, which I may come back to if and as this thread develops. However, I leave you with an interesting thought. The small rig (despite the aspirations of the original rule makers about sailing in light winds and heavy winds) is not a ‘storm’ rig at all. It is a rig to be used in (say) 25% of all races. The consequence of this is that the logical choice of boat for conditions in, say, Florida is not one carrying clouds of sail, but one with a very light, narrow easily driven hull that will carry its B rig (let’s call it that) from 6-7 mph upwards, or perhaps even less. So far as I know, nobody has gone down this route, but the logic appears incontrovertible under the existing rule.