That's the media for you. CSS Hunley had a spar mounted charge that was rammed into the Housatonic's side. The Hunley then backed away and fired the charge with a lanyard. The shock underwater would have been brutal.
If you get to Charleston SC, it's worth the detour to go see her at the Lasch Conservation Center. I did, and it was incredible.
Thanks for the information. I am up North, but my father is now retired and tours Civil War sights. He fell in love with Charleston and has since taken my mom a few times. Must be quite a place.