A learner in light air.
What would any of us do knowing a boat was coming to within 5 metres of us at 50 miles an hour in the dark???!!!!!
Flare gun fired at approaching boat's driver. Yes, it's not legal, but damn is it effective (unless there's an auto-pilot engaged).
In my opinion, a flare gun should always be by the skipper or watch captain at night (safety on), if for no other reason than a MOB illumination