Periscopes and other holes question!

[Rhodes]

When thinking about submarines, playing the sims and seeing some film about the them, always had a few questions about how some sub systems work.
Using google to search is a normal thing this days, but I lack the correct terms or got the same thing and that is not what I am looking for.

My question about periscopes is not how do they work, but more how they are watertight, specifically the all system and not just the optical part. And one can focus in WW2 subs, since latter ones would use the same principle and earlier ones probably the same.
So, are the periscope wells watertight, and how? Do they have some kind of lid/door (rubber/metal) that opens and closes? If so, those are design to withstand high pressure, correct?
And if one decides to raise the periscope at 100m or 150m, what consequences would that act provoke? (hypotetical question, I do not even if it is possible to do so).
And the voice tubes form the towers to the control room? Logic tells me that they can not be full open, they have valves?
It was always that bothered me in terms of knowledge. Even more in seeing photos of the towers and the periscopes. Some had a metal lid attach to the well, but in a crash dive situation no one would put the lid in place (I think). Other pictures one can see the periscope head, so decided finally to ask here for some knowledge and of course, if there are websites about the subject, I appreciate knowing them also.