Sail unarmed into pirate waters.....get seized by pirates

You've probably heard about the Maersk, Alabama, a huge container ship that was hijacked by a rag-tag band of Somali pirates yesterday. The crew of about 20 Americans is being held hostage. I want to know how a skiff the size of a row boat can attack and disable a crew of 20 on a cargo ship of this size?

Here's the ship, or one exactly like it, that was hijacked. And below is a boat filled with "pirates" like the one used to capture the container ship.

You're telling me that a single dude with a sniper rifle couldn't kill every one of these guys before they even approached the ship, much less climbed aboard? He wouldn't even have to kill them, just shoot the outboard motor and disable the boat.

Why don't these ships that sail anywhere near Somalia have at least one guy whose job it is to empty magazines of bullets into any approaching boats? This is sort of like a doughnut truck driving down Rosie O'Donnell's street and expecting not to get hijacked. But maybe I'm missing something.