[An Old Man]

A couple of rounds from a 30-06, .308, (your favorite round here,) deer rifle with a scope would be the ticket.

The pros tend to use these things.

[The KG9 Kid]

Your minigun 'tis but a popgun.

Here's real maritime ship defense against small fast watercraft:

http://www.youtube.com/watch?v=C1RnHiEDNQ8&feature=related

[D Rider]

The pros tend to use these things.( picture of mini-gun)

My point was that any deer rifle would out class the pirates. The gun you showed is overkill on anything under the size of an Elk herd. ;)

On second thought, when shooting pirates, you really are not concerned with the quality of meat that is left.