To IMCA of Australia,

Due to the polarised opinions in the class with regard to the use of hydrofoils and the expectation that some measurement disputation may occur during the Munmorah Nationals 2002, requiring adjudication by the National Measurer, I have firstly asked the National Secretary to instigate a vote or ruling from the World Association. That in turn will require endorsement from ISAF.

As such a ruling can not be organised or decided this year the best I can do is study the existing rules and make an interpretation based on a considered analysis, which I will use in deciding measurement disputes if they arise at the Nationals.

The following contains that analysis and my interpretations. It will be issued with the NoR for the Nationals so that all Moth sailors intending to sail will know what interpretations will be applied if I am needed to adjudicate in any measurement dispute.

Phil Stevenson, 28/9/01
NSW and National Measurer

Interim Measurement Interpretation on Hydrofoil Moths

This considered response is to try and quell a serious debate not about the merits of Hydrofoil Moths but about their legality under the existing rules. I think it is important for Australia's Moth sailors to know what rules will apply at this year's Nationals prior to any explanatory ruling from IMCA or ISAF.

Rules as applied to pre foiler boats:
Our rules are as published in 1972 and last amended on 28/12/94 and are available here on the World Moth site. (This version supersedes and varies slightly from that included in the National constitution available on the same site.)

The rules distinctly separate the spars and sail from the hull. The specific hull rule separates the rudder and fittings. The remainder of the boat by inference must be covered by the rule 6 covering the hull.

Taking into account boats that existed at the time of the drafting of the rules, it is assumed that removable centreboards are not included in the tight tape restriction on underwater hollows in rule 6.2 iv.

Adaptation of the existing hull rules to cover foiler concepts.
T foils on rudders were accepted long ago and should not be included in any foiler response. The rudder and fittings are excluded from the hull measurement whether teed or not.

All other parts of the boat must fit within the overall length and width restrictions of rule 6.

Because it would be difficult to decide if wing mounted foils provided enough buoyancy to be classified as hulls, and without guidance from IMCA or ISAF, at this stage I am not prepared to interpret that Wing mounted foils, as we have seen demonstrated so far, are contrary to the sailing as a multihull rule 6.2 i.

INTERPRETATION - Trifoilers are not Multihulls

With regard to rule 6.2iii concerning longitudinal air gap and similarly rule 6.2 iv concerning the below waterline tight tape, if removable centreboards are excluded by long precedence, it could be inferred that removable foils in any location are also excluded. Removal should include retraction or folding so that in the retracted position the boat complies with the rules, ie. the foils are clear of the static waterline and hence not subject to the tight tape or air gap rules. This would allow a foiler to be classified as complying to these rules provided the foils are removable.

INTERPRETATION - Removable or retractable foils or centreboards are not included in air gap or tight tape tests - rules 6.2iii and 6.2iv. To this extent I would define removable to be the same as a centreboard. ie. able to be installed and removed or lowered and retracted by the sailor alone, without tools, while the boat is afloat, as when launching and retrieving. In the retracted position the hull (including foils) must comply with rules 6.2iii and 6.2iv.

The consequence of this is that foils attached with bolts are not removable in this way. Fixed wing mounted tri-foils when measured afloat would fail the air gap and tight tape rules 6.2iii and 6.2 iv.

Changes in Configuration
Rule 3.1 requires all boats to have a measurement certificate (note the singular).
Rule 3.7 requires the owner to have the boat remeasured and the certificate endorsed if the boat is altered or (components) replaced. Provision for multiple sails is covered in rule 4.4.

If the skipper of a boat with removable foils as interpreted above decides to change from using say two wing foils to a single centreboard during a regatta, I consider that this is a change worthy of re-measurement and certificate endorsement. The mechanism for this is not defined and no sailor should expect such special treatment form voluntary officials between races at the regatta.

I do not think it is intended that boats carry two or more certificates covering different configurations, and as I do not intend to be available to measure boats after a regatta has commenced, I interpret the rules to prohibit any changes of configuration during an event.

INTERPRETATION - Changing between a conventional configuration to a trifoiler configuration during the regatta is not allowed during the regatta.

T foil Centreboards: I think changing between a Tee centreboard and a conventional one is probably OK if the Tee is within the scale of a normal Tee rudder. This would not require re-measurement.
If the Tee centreboard is wider than the hull and/or has a trimming device, I think that is a design change and could not be changed for a conventional centreboard during the regatta.

Phil Stevenson, 28/9/01
NSW and Aust IMCA Measurer