It is mandatory to wear a helmet made to a minimum standard to include
UN ECE22-05 or Snell M2000, or M2005 or Snell SA2000 or SA2005.
Helmets must have temple protection and must be coloured fluorescent
orange, fluorescent red, fluorescent yellow or international orange
colour. These helmet Colours must be bright enough to be clearly visible
in the water. Helmets must have the boats race number provided on the
top and to be easily read from behind. Minimum height of 7.5cm
(75mm). This can either be painted in black or with the use of adhesive
Probably worth looking through the Rules !!