[Paddlewise] Whistles or Pistols

G'Day,

On a couple of occasions now I've experienced people in trouble who have
blown the mandatory whistle and noone has heard. Fortunately they were
spotted as missing and in trouble, but its been a little close for comfort.

On the last occasion the question of carrying flares and mini rockets came
up and someone mentioned that minirockets when fired went off with quite a
pistol crack. Is this true? If so could it be a better alert system to
supplement the whistle, on the other hand its a bit undesirable to set off a
minirocket just to attract the attention of someone in the group. Made me
wonder if there was something akin to a cheap waterproof starter pistol that
could be used instead of a whistle?

All the best, PeterO