
The MK-9 SDV is very small, carries a two man crew and is very uncomfortable to operate. It was a weapons platform to deliver two MK-46 torpedoes.
This answers John Coffey's question from this morning on whether or not you could arm a very small mini-sub with torpedoes.
There were still two MK-9 SDV platoons when I was at SDVT-One (a reservist at the time) in the early 1990's. I have heard that they retired the MK-9.
Museum photos: