By all accounts USS Housatonic was a fine, bluff vessel, a screw sloop of 1,200 tons and a conventional broadside weight of metal somewhere in the range of a thousand pounds. By the standards of the mid-1860s she was a sturdy blockader that had captured two valuable prizes in three months soon after she took station off Charleston. She had bombarded Fort Wagner (of Glory fame), and had landed more than one raiding and scouting party around the Charleston defenses.
But on the night of 17 February 1864, she had the ill luck of encountering an enemy that she could not overcome. H.L. Hunley, a Confederate submersible, rammed her spar torpedo into Housatonic just after 9 PM, blowing a hole in the sloop big enough to drive a pony and trap through. The issue wasn’t in doubt, but Housatonic only lost five men.
Hunley went on to fame and glory in the popular press mostly because she was the first submersible vessel to have sunk an operational warship, not because she was a successful vessel. She was lost with all hands–after killing two other crews including her inventor, perhaps that was for the best. Hunley was discovered and raised in 2000; her victim’s location was well marked in charts (albeit as a hazard to navigation) until the early 20th century, and only her anchor remains.
So a hundred and fifty one years on, what’s to be said about the emergence of undersea warfare? The introduction of the submarine to commerce warfare would change the nature of naval war itself. The submarine was at first forced to observe conventional and unwritten “cruiser rules” that required they stop and search their intended prey, giving their passengers and crew an opportunity to take to their boats. But in the press of war that honorable option soon gave way, as honor often does, to expediency. Targets didn’t stop; weather was hazardous for small submarines to try to come alongside; Q-ships became a menace. By 1915 cruiser rules were abandoned, and by 1917 unrestricted submarine warfare, where submarines were shooting anything not bearing an Imperial German flag within an exclusion zone around the British Isles, was a horrible reality. That, eventually, would lead to even worse luck for Germany, and also to Japan a generation later. Today, cruiser rules are usually regarded as merely quaint.
So Housatonic and her five crewmen , blockading Charleston Harbor on a cold night in 1864, were the first of many hundreds of ships and many thousands of people who would be unlucky enough to be killed on cold and dark nights by unseen attackers.