Not much is known for sure on the mini-sub. It showed up a couple days ago and spent a little time in the assembly bay. It is now parked in a high visibility area along the highway border of the DDI property.
These are what we (or at least I) "think".
Looks like a manned sub vs AUV since it has viewing ports on the "conning tower". It looks like a shallow and short duration sub, possibly a "wet" sub meaning not sealed, it which case it would be similar to SCUBA with no protection from pressure.
Being parked out front seems to be for the purpose of getting attention.
There was a rumor that someone has a radio jammer that plays the Beatles "Yellow Submarine" song on all car radios as they pass by. ;-)