  The east african seafarers association estimate that there are at least 5 pirate gangs operating with a total of over 1000 armed men. You'd need a small warship with fully armed torpedos to resist an act of piracy. This is also another reason why any such UK military operation could result in complete disaster.   They don't all attack a single vessel at once, a small boat usually does the attack. Either way I would rather have a gun, much better than simply using harsh language.