What the heck I just researched this same subject for ttsimmons. The answer is in your race instructions and if the RC did a really bad job and did not give you any then I suppose that any start at any time before the starting line becomes a finishing line would float and shame on the RC for not doing their job. If how ever you had an early start then the default rule gives you 4 minutes to get back on the start side of the line. unless modified by RC instructions wich you aparently did not have. My $.02