-Toeofdoom - gas grenades? Rolling Eyes you play too many games, boy
games...? what games even have gas grenades...? and i dont play many computer games... Is there something wrong with the idea? It would be a way to disable the raptors without killing any humans, and would hit any hidden raptors aswell. Atleast thats if we could find a gas that would do that... it would be a great advantage to have.
the main city area is raised above the rest of the island, along with vital things such as the farms, etc.
I already mentioned farms :p
And yeah, other things you mention: 150 people or so is good, you can learn to know that many people on sight, but still have enough variation that it doesnt seem really small. 100-250 would be a possible range though.
How high would the main deck need to be? We wouldnt want sea water getting all over the plants, unless we had extremely salt tolerant ones, and solar cells, so they might have to be raised a fair bit really.
Anyway, so basically we start with a giant floating cuboid type thing, mostly underwater. If we had say, half our food as plants from the farms (meat uses up alot more space) and half as seafood, how much farm space would we need? i suppose the amount you said seems reasonable. A few smaller boats would be used too for fishing and trading, all crew members armed there atleast, where allowed by local law. Also, we could trade with a bunch of other countrys for food we could not produce ourselves, such as the meat products and eggs/milk.
Water is from rainwater and a few purifying plants i guess. Heavy machinery like the water purifiers would be on the bottom decks partlyas ballast i guess, along with any propulsion machinery, sewerage treatment plants, etc. Those things would be good to have mainly robots working on.
Also, I would reccomend having the wind farm things all over the island. like, fit them between solar cells and farm sections, because they wouldnt block out too much sunlight anyway.
I can get to work on a plan if you like... :p or a 3D model type thing.