[forgotten man]

I think the British used a similiar technique against the U-Boats in WWI. They were called Q-Boats. They were freighters with hidden guns that blew away German subs on the surface.

[muawiyah]

There were hundreds of U-boats destroyed along the US East Coast ~ a variety of techniques were used. Eventually there were no more U-boats.

The singular solution in every case was to poke a hole in the hull!