User blog comment:Unownshipper/Flora and Fauna of Rapture/@comment-1592487-20131106045727/@comment-6024608-20131106081839

I looked at the depth problem  (too deep and water pressure causes the BS sci-fi  to have to turn into Infinite -- pure 'do anything you like' fantasy)

Keep counting as you last saw 18 fathoms, after window is covered til it opens again (and you are moving sideways) -- and it thus is deeper than that. I estimated about 400 feet and the you enter the building with many floors still shown below.

Rapture is on an old sea mount (underwater volcano... source of geothermal power) that nearly reaches the surface (where the lighthouse is built). Otherwise that part of the ocean floor is around 2000ft which is quite too much. You still want it deep enough that the infrequent iceberg doesnt take off the tops of many tall buildings  (tops 200 feet deep enuf??)  Bulk of the volcano close to the surface,  when the city is built in its collapsed center, could largely block icebergs.

600 foot deep at the base 'street' level for most building (giving you ~400 feet height for tallest buildings). Still too deep for divers, but automation for construction was mentioned in the novel and much could be prefabricated nearer the sufface.

The view out the windows cant be right anyway because no light would show them past 400-600 feet distant -- so they are exagerations in distance and closer than they appear and thus smaller than the number of windows/floors indicate (some indicate like 60 stories of windows).

20 atmospheres of pressure (at 600ft) is handleable with 1940s era tech, if not a bit expensive (most of the buildings would be thick reinforced concrete... Those big flat window panes  would need revising -- even worse/rediculous in BAS)

Much would be decoration (top 1/3 of buildings)  to get the look of the Manhattan Skyline, if not in extent/size (also thin sections and thick walls is not efficient for living interiors, so most real living space is in the squat fortress europa style buildings below)