I've taken on armed trawlers with my deck gun now and again. I once duked it out with a flower, he found to his cost I wasn't a pansey! I then took on a C class destroyer, but realising I was out gunned I submerged and took him out with a stern shot.
I did this insane thing because I had attacked a convoy, and wanted to go after some crippled Merchants that still floated. Just remember not to get between me and my prey, and we'll get on fine!
