and you better understand the consequences when and where and how you use a flare gun for a deterent.
then like any wrapon, you better practice with it more than the once or twice most boaters may have fired one into the air for practice.
my cut, is if you are willing to use a flare gun.... much better to get, use, practice with and understand the laws of owning a real gun.
like most topics here on TF, use the rigjt tool for the job, do the job right the first time....anything else can go sideways quick.
also, even flare guns are considered weapons in some jurisdictions.... know the laws.