D&D 5E Casting spells with a Verbal component underwater

[Coroc]

Sound is not conducted through space; but space is not a silence spell. It doesn't prevent you making sound, it just keeps anyone from hearing you unless they are in physical contact. You can hear yourself speak, because the sound goes through your own body. If you put your mouth on someone else's ear, they can hear you.

That said, if you're unprotected in open space, you had better speak fast because the vacuum will suck the air out of your lungs very rapidly, and trying to hold your breath will rupture your lungs.

Yea you better prepared "Etherwalk", "Breathe vacum" and "Phandaals propulsion jets" to survive

Sorry for my unscientific description of the phenomen, i was in a hurry. Although i can even think in english i am a non native speaker and somtimes this shines through.

You want to hear some other fun fact: Back in the late 70s when Star Wars came to the cinemas, someone i know, was working for the Space shuttle program. Politicians, who had to finance these projects, were sometimes briefed by him. Some of them totally believed that the space shuttle, which can of course manouever a bit when in Orbit, but has its main engines mainly for take off, would be able to fly around up there like the X-Wings they had seen in the movies and some were even asking if the shuttle should not be armed with star wars like laser guns also

They were a bit disappointed when confronted with reality versus movies