We have talked about private submarines before. They are way cool, way expensive and I want one.
Here are a couple of more of these that you might want to have a look at for your collection, that are much smaller than the other one we talked about.
The Nexus holds upt o 9 people, costs between $2 and $3 million and will dive to 200 meters.
The project Neptune Trident has versions that hold 2 or 3 people, costs about $3.3 million.