for me, one aspect of a seastead is the isolation from supplies. living in the boonies i tend to have everything needed to survive for several weeks with absolutely no dependencies on the outside world. well within some practical limits. so i would have backups (sometimes several) of all critical infrastructure, tools and parts to repair most things along with a small machine shop, above average medical supplies, and overkill on monitoring equipment for environment and systems status. like, lots of stuff like that. i live in the boonies, and ive learned that if you dont have it with you, you dont have it period. simple enough thing but when the stores are a dozen miles or more away in rough seas for unknown period of time thats the same thing. so any seastead i design will be pretty big. living quarters would be a small part of it. command and control will be as redundant and as state of the art as i can make it, after all, when you get down to it this is a sea going vessel that my life will depend on. so costly for the specs that i am comfortable with, which are admittedly above specs a typical seasteader may have.
dont get me wrong, the isolation and self sufficiency is a good thing for me, but a lot of planning goes into that. its not just the base platform which worries me, you guys seems to have those problems licked. its the rest of it that i worry about. ive learned to only trust critical infrastructure that either i design and build, or is so well proven i can adapt off the shelf items for my use. i have no intention of getting into some life threaten situation that i could have avoided because i skimped on kit loadout.
We're about 20 minutes to the closest restaurant by speed boat. 30 minutes and a ride through traffic to the nearest hospital. Where I lived before it was usually an hour drive in traffic to the main shopping area so you just go a few times a week or less.
Though I am in the process of buying a small sail boat. It has an engine and I'll add an outboard for redundancy. Plus the sail. So a liesurely ride into town could take an hour or so.
under ideal conditions sure. im thinking of worst case. im not really a pessimistic type but when it comes to survival, i plan for pretty bad conditions. and some of those plans have paid off big time. a tornado in town and a freak snowstorm that caused a 7 day multi state wide power failure affecting most of those states population on the east coast and that made many roads impassible for days (even with a pretty serious 4wd with mods), most fuel stations inoperable (no power to run the pumps), pharmacies having problems keeping meds in stock (statewide travel bans on some highways), stores running out of food and lots of the refrigerated stock they did have going bad because no power, plus limited resupply made me glad i had a weeks worth of fuel for my genset thats capable of running most of the house (just the electric stove and electric cloths dryer is excluded) and a transfer switch to do it right and make it wife safe, food for a month with several cooking sources with different fuels, lots of stocked up batteries, extra meds, tools supplies and equipment to fix the genset etc. not all of it was needed but i slept well knowing the wife and i were good. but it sucked big time for many, and especially hard for those with electric powered medical equipment. most of the unprepared just had no fuel, no heat source and no food, pretty big inconveniences.
and thats on land. storms and their duration are unpredictable. how big is that boat anyway?
a seastead of course will have different failure modes, but there will be failures and they will happen a the worst times, like when you cant get to land with what youve got.