To go deep enough not to be bothered by the waves, the whole thing would have to be just as strong and air-tight as any submarine. Not to say it isn’t a good idea, though. I think some people are considering ways to do just that, though I haven’t yet seen fully developed ideas on that one yet.
This isn’t the case. I’ve beaten this issue to death, but I’ll say it again: submarines maintain 1 ATM pressure because they are intended to keep nitrogen sensitive flesh bags like you and me at a comfortable 14psi.
SUBMERSIBLES can be made of seran wrap so long as they are capable of diving and surfacing: their only engineering requirement is corrossion resistence.
Given a scuba tank, I can keep your ipod dry at the bottom of the ocean, but I’d recommend it’s owner stay no deeper than 5 meters for extended periods, however with the assistence of dive tables: it is possible to go much deeper in order to hide from a storm for short lengths of time.
Once this concept is understood, virtually every assumption regarding conventional seasteading engineering becomes moot, and the ease by which a storm can be survived becomes apparent. I could build a single person seastead that could survive outside of port and inside the USA’s EEZ for < $3000. Hell: I can build a raft capable of survivng a 100 year storm for ~$300. I just wouldn't want to live on the thing for any longer than necessary. For the amount of elbow room $300 buys: you might as well be in solitary confinement.
A pressure hull is a matter of comfort, safety, and long term cost efficiency.