So I think I decided what I want for Christmas… A Scubacraft (I saw it in Wired magazine).
It’s basically a boat that you can hit a button, and it will go underwater (up to 100 feet). It would be pretty awesome to go scuba diving and instead of leaving your boat at the surface, just take it under water with you when you get to the dive site. It’s not pressurized, so it’s not a submarine (you would still need scuba gear of course).
It also has an onboard computer that controls your ascent and descent so you don’t go to quickly and give yourself the bends.
I love you, Santa!