I wouldn’t recommend a speargun for self-defense; a jury might consider it a bit . . . cruel. Then again, gun laws deny millions of law=abiding citizens their natural, civil and (in America) Constitutionally protected right to keep and bear firearms. If that’s the way you roll, for whatever reason, needless to say, Herr Sprave’s +p++ and two-shot version offers improved penetration. It’s a clever innovation for those of you who think you might have to recreate Thunderball on land. Just remember to laugh maniacally.