Darn it, I figured there was a catch somewhere.Not sure, if you don't cross the start line sometime after your prep signal (i.e. while racing) doesn't the RC just score you DNS? The SI state that each boats prep is 4 minutes before their start. So a boat crossing 53 minutes early would not be racing at that time.
(oh and yes the other stuff still applies :0)
We occasionally have problems with boats messing up other boats' starts in our pursuit races; when I'm race committee I deal with it by informing them that their parking permit for the social afterward will be revoked.
I don't think that's in the rules but it keeps everyone playing nice