Wind direction may change so squaring of the line may become necessary. Don t forget to hoist it again. Check wind velocity, time of day, weather conditions. Write down course to be sailed and time of each fleet start. Combining of fleets is permissible.
Flags always take precedence over sounds in starting sequences.
It is the preparatory signal, to be drop at 9 minutes. RED flag with 1 horn at 10 minutes start of 1st race. For rolling 5 minute starts drop this flag 4 minutes later. 1 minute later raise it again with 1 horn. Continue process until all fleets have started.