ANSWERING YOUR HYPOTHETICAL QUESTIONS WITH PHYSICS, EVERY TUESDAY.
But helium has a trick. When cooled below about two degrees kelvin, it becomes a superfluid, which has the odd property that it crawls up and over the walls of containers by capillary forces.
It crawls along at about 20 centimeters per second, so it would take the liquid helium less than 30 seconds to start collecting in the bottom of your boat.
This would, as in the liquid nitrogen scenario, cause rapid death from hypothermia.
If it’s any consolation, as you lay dying, you would be able to observe an odd phenomenon.
Superfluid helium films, like the one rapidly covering you, carry the same types of ordinary sound waves that most materials do. But they also exhibit an additional type of wave, a slow-moving ripple that propogates along thin films of helium. It’s only observed in superfluids, and has the mysterious and poetic name “third sound.”
Your eardrums may no longer function, and wouldn’t be able to detect this type of vibration anyway, but as you froze to death in the floor of a giant boat, your ears would be filled—literally—with a sound no human can ever hear: The third sound.
And that, at least, is pretty cool.