From the History.Navy.mil site.
Also called the St. Patrick. Small semi-submersible torpedo boat, privately built in Mobile in 1864. (Jones' report made it sound like it was built at Selma.) Operated under Confederate Army control but had naval officer in command.
Attacked the USS Octorara in Mobile Bay 28 Jan 1965, but torpedo misfired and the Union ship wasn't damaged.
The Saint Patrick was able to escape return fire and return to Mobile.