User blog comment:Unownshipper/Metallurgists Wanted: Rapture's Natural Resources/@comment-75.36.142.53-20140810162926/@comment-75.36.142.216-20140811035128

Those aren't  deep-sea pressure suits. Those are classic diving dress made of canvas and pumped up to match the sea water pressure and those divers wouldnt operate any deeper than scuba (just 150ft  is highly dangerous). Pressure hard suits make you look more like a bulky robot (and are about as clumsy and complex). That artists rendition could be as likely as the epic Ryan pointing at the Ocean and saying  "We Build Rapture There".

The Novel author realized that and talked alot about automated (remote controlled) machines for alot of the construction.