Situation
An international one-design dinghy class has been developing and using their own arbitration system at most of their international class events since early 1990's. The notice of race mentions that such system may be offered, and the system is described in detail in the sailing instructions. The use of arbitration is limited to boat vs boat incidents. The system is voluntary, however, if the competitors accept going into arbitration they also agree to accept the decision of the arbitrators as the final decision. An arbitration may be reopened under rule 66. Two members of the international jury will be the arbitrators.
Rule 70.5 state that the decision of a properly constituted international jury cannot be appealed. 

Question 1
Will a decision by the arbitrators be final as stated in the sailing instructions or could such decisions be subject to an appeal?

Answer 1
An arbitrator’s decision is not a protest committee decision under the Racing Rules of Sailing and therefore it cannot be appealed. This applies whether or not the protest committee at the event is an international jury. When the parties agree to use a described arbitration system that prevents further proceedings following the decision, they also agree to decline their rights to appeal.
However, sailing instructions may define other arbitration systems with different rights and obligations for the parties.

Question 2
Is the international jury acting outside its mandate by deciding protests using this arbitration system?  

Answer 2
No.

Question 3
Is it acceptable that the sailing instructions introduce a 'non-appealable' system?

Answer 3
Yes. As this is an optional and voluntary system, it does not remove the competitor's right to choose a regular protest hearing instead. However, when there is an international jury, the choice is between two non-appealable systems