Is it possible to have a ship that can travel through air and sea?

Q2: is it also possible to have a ship which can travel underwater, on water, in air and space?Is it possible to have a ship that can travel through air and sea?Well there's no physical law that prohibits it.. it's just a matter of genius engineering and cash.Is it possible to have a ship that can travel through air and sea?Aircraft with pontoons can travel on both water and in the air. Some of the earlier commercial aircraft were quite luxurious, like the Howard Hughes aircraft (Spruce Goose); so they were tantamount to yachts with wings. [See source.]



But the bottom line is the bottom line. The need for speed, the flying part, and the need for cargo volume, the ship part, are at odds. That is, to build a craft for one thing meant to compromise the other thing. In the end, it's possible, but not economically feasible.



The underwater/flying craft, however, is probably less likely because to survive the extraordinary pressures under water, the craft would have to be super strong and, therefore, heavy. And that is at odds with the need to be light for flying craft. So the underwater craft is probably economically infeasible plus physically impossible due to the weight/strength disparities.



There is a notable exception here... ASROC, the U.S. Navy's anti-sub missile. ASROC flies off destroyers when launched, goes a preprogramed distance and bearing, and then dives into the water to seek out and destroy enemy subs underwater. So these guided missiles do fly and then swim underwater. But for much larger, commercially used craft that fly and swim, the physics and the economics indicate the underwater flier is not likely.