Engineeering house Innerspace has come out with a second, bigger, badder, more porpoise-y version of their first personal submarine, The Dolphin. The new iteration is called the Seabreacher which makes me want to perpetrate underwater incursions with a foxy lady-spy.
The design is based on F-22 Raptor fighter cockpits because, as the manufacturer says, "Keeping Seabreacher afloat and totally water tight under all conditions was a top priority." I'm not an engineer or anything, but that does seem rather important.
It's got a 175hp engine in the prototype, but there is a 250hp, supercharged version of the same engine which would fit the Seabreacher if you wanted to do things like this:
Sadly, the Seabreacher is only available for people looking to race it or participate in demonstrations. This means your average nautical enthusiast probably can't get one without corporate sponsorship. However, at least it's a stroke in a cool direction for the wetter of us gearheads.