my preference would be to keep the 1 hour,nautical mile, best of 5-10 sec ave (same as gpsss) alpha,2 sec for navi (display speed foretrex) and (not sure how you would implement this ) some way of scoring points for number of times sailed.
i thought the challenge idea was supposed to foster the social aspect of sailing the number of times sailed would deal with this to some degree by virture of the fact you would be at and on the water more often.
the distance thing i dont really have a problem with, how ever i do,personally, find it to be a bit of an anti social aspect of the sport and at times, a boring, repititious low quality form of wind surfing-thats if its possible for sailing to be boring

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of course this is just my opinion,
at the end of the day the whole concept has been a great success and i would have no probs with it staying with the current format if thats what the masses wanted.