(a) In all competitions a combination of audible and/or visual signals shall be used to signal:
- (i) The start of heats or rounds – one blast of siren/whistle and green flag raised.
- (ii) A 5-minute warning prior to the end of a round – green flag lowered and yellow flag raised.
- (iii) The finish of a round – two blasts of siren/whistle and no flag raised.