Another option would be to do what they do at major sailing regattas which is to have an over early flag to let the whole fleet know if there is someone over early and if the flag goes up, it is up to that rider to restart the race by sailing back to the other side of the start line and restarting the race. there would also be a flag that would disqualify you if you are over early and to leave it up to the race committee to decide which flag to use. there would also have to be an easy way to identify riders such as jersies with numbers or even back to the sailing way and have kite numbers.
Preparatory Flag(s) Meaning
P Normal preparatory signal; no starting penalties are in effect. So if you are over the line at the start you can return through the line or round the ends. Remember that you must keep clear of boats not returning
I The Round-an-End Rule 30.1 will be in effect. If you are over the line during the minute before the start then you must sail to the pre-start side of the line around either end before starting.
The 20% Penalty Rule 30.2 will be in effect. If you are in the triangle formed by the ends of the line and the first mark during the minute before the start you will receive a 20% scoring penalty. (20% of the number entered or as dictated by the sailing instructions)
Black Flag The Black Flag Rule 30.3 will be in effect. If you are in the triangle formed by the ends of the line and the first mark during the minute before the start you will be disqualified.
I & Z Both the Round-an-End Rule and the 20% Penalty Rule will be in effect during the minute before the start.
this is copied directly from the ISAF sailing website. here is the link to the page which explains it better but it would be a better alternitive to going through all the trouble to go and travel than get disqualified...although the best solution is probibly to just not be over early!
http://www.autohoot.com/isaf_change_starting.htm