Pressure at the Titanic’s depth is 380 atmosphere - changing the pressure from 1 to 54 atmospheres wouldn’t make much difference, plus it would mean the ascension to the surface would take significantly longer due to the risk of decompression sickness. In this case, about 3 weeks.
Based on the depth the sub imploded at the effective reduction in pressure differential of 54 atm would have prevented the implosion, also the hull may not have accrued damage over time to the extent it did had it been exposed to lower pressure differentials. It probably would have failed at some point, but maybe much later on in it's life.
I'm not sure that the passengers would reach saturation during the time spent at that pressure so not sure it would be quite that long for decompression, but a pressurised habitat on the surface such as that used by saturation divers could be used for a slow decompression. But that would cost money and I suppose kind of defeats the whole point of the sub being done on a shoestring budget with inadequate testing, you'd probably have another Byford Dolphin style incident if Oceangate tried doing it.
www.lbc.co.uk
