At a recent club race... winds were very light prior to the start of a race, and the officer of the day announced via radio that boats could motor until the 1 minute signal (5 minute start sequence). Is this allowable under rule 42.3(h). A search of the ISAF website provided little guidance on this new rule.
In response, I assume that the "5 minute" sequence referred to maintains the standard preparatory signal at the 4 minute gun, which means that the rules begin to apply at that time. The new Rule 42.3(h) reads:
Sailing instructions may, in stated circumstances, permit propulsion using an engine or any other method, provided the boat dos not gain a significant advantage in the race.
I do not know the origin of this new subsection, and if any reader does, please comment below. Though I haven't read the SIs that apply to the race in question, it is my interpretation of 42.3(h) that if the SIs make allowance for the use of the engine for all boats, then none gains a significant advantage if it's a one-design fleet. If it's a mixed fleet, there may be significant speed differences in engine power that could leave someone coasting longer after shut-off. A Macgregor 26 on full plane might coast for well longer than one minute!
Since the other racing rules apply at the prep signal, having them in force while boats are motoring around seems problematic. I'm not a PRO, but I think a better way to go is 1) sit and wait for breeze, 2) abandon and go play frisbee, or 3) change the prep signal to the one minute gun, let them motor around until then, and then turn off the engines and turn on the rules. As for this case, unless someone can make a case that a boat had a significant advantage, this seems like a permissable, though possibly unintended, consequence of the new 42.3(h).