If this leaked transcript of the text messaging between the Titan and the Polar Prince are true, the five of them had to deal with 20 minutes of shear terror in realizing they were in deep trouble. The transcript also supports the speculation they had an early warning something was wrong with the pressure vessel and they tried to abort the dive by dumping ballast. Of note from this video is the rate of their decent being too fast and their ascent was too slow after dumping ballast.