There is never a right time to be controversial but since there has been a small discussion here about rules recently have a look at the photo below and ask yourself if this adjustable diamond tensioner is in the spirit of the rules!! The owner could possibly argue that this mechanism is never used during a race scenario but the ease in which it can be adjusted would be open to abuse!! I have checked the rules but still could be wrong but adjusting diamond tension during a race is prohibited.

This it?

http://www.formula16.org/content/view/13/36/lang,en/
"1.7 Rigging and equipment

1.7.1 It is not permitted to adjust the following items while racing: the rake of the mast, the tension of the standing rigging, the angle or length of the spreaders or the position and height of the gennaker boom.

1.7.2 It is permitted to adjust the diamond wire tension while racing or to adjust the items named under 1.7.1 between races."

Hi Simon
I thought I was going mad but I knew I had read this somewhere:
Other main rules
* Mid height width of gennaker is at minimum 75 % of length foot.
* Boat must be rightable by any crew either solo or doublehanded
* The rig may not be trimmed between start and finish by other means than sheet, downhaul, outhaul, traveller, mast rotation and halyards systems.
* Only "soft" sails are allowed.
* Using multiple sets of the top three battens to fine tune the rig to the crew (1-up/2-up) is permitted and does not require remeasurement of the sail
* No ballast other than corrector weights are allowed
* The wearing of bouyancy aids is compulsary during (open) Formula 16 races

Therefore it seems as if we have a contradiction in our rules? <img src="http://www.catsailor.com/forums/images/graemlins/confused.gif" alt="" />

May be it's not so much as a contradiction as it is that I have got confused over definitions. When I saw the word rig I instantly thought of standing rigging, but I think in this case rig means the sails. SORRY.

I would define Standing rigging as:- All lines/wires used to support the mast.

I believe the ISAF definition is pretty much in line with that. Would have to check to be sure.

So I guess the issue comes down to which of the F16 rules has priority. 1.7.2 states you can adjust the diamond tension during a race.

However in the "main rules" section it's stated that: The rig may not be trimmed between start and finish by other means than sheet, downhaul, outhaul, traveller, mast rotation and halyards systems.

The above rule seems to contradict 1.7.2

I think its a big stretch to say that you are using a sheet to adjust the sails... via the diamond tension.

Are there measurement certificates for F16?