The destroyer Captain gets on the loud-speaker and shouts, "Ahoy, small craft.  Where are you headed?"

One of the Muslims puts down his oar, stands up, and shouts, "We are invading Britain".

The entire crew on the destroyer doubles over in laughter.
When the Captain finally catches his breath, he gets back on the loud-speaker and asks, "Just the four of you?"

The same Muslim stands up again and shouts, "No, we're the last four. The other three million are already there!"

Nobody on the destroyer laughed. 

Aussie Paul.