In the Rifters Trilogy, is the Rifters' maximum survivable diving depth established?
I checked the old Rifters website and found no mention of maximum depth, but there is information on the depth and pressure of the Channer Vent.
You're three kilometers below the surface of the Pacific Ocean.
From the page about the Rifters themselves:
Here's the problem: the same conditions that make hydrothermal vents such hotbeds of geothermal energy also make them veritable deathtraps for anything born on the shallow side of 2000 meters. Seaquakes, thermal eruptions, and mudslides are common. Hydrostatic pressure is over three hundred times surface-normal.
There is a map of the Channer Vent on the site, and the depth legend goes to 4900 meters below sea level. I can't remember if any characters went to these particular parts of the rift, but if they did then we can defintely say they survived a depth of 4900 meters. Otherwise, we know for sure they were operating at a depth of at least 3000 meters.
Also, I'm just happy to see a Rifters question! I love that series.
It's not spelled out anywhere, but since the Rifters' bodies have been modified to equalize internal and external pressure without killing them, the implication is that they have no maximum depth. I've read the first two books and don't recall any maximum depth ever being mentioned for the Rifters. This paragraph from Maelstrom is the only cite I can find for this, though.
Of course not. Let the surface-skimming tourists breathe from their clunky tanks, risking narcosis or the bends whenever they ventured too far from the surface. Let them suffer nightmares of exploding lungs and eyes marbling into clusters of fleshy bubbles. Rifters were immune to such worries. Inside Beebe Station, Lenie Clarke had breathed at sea-level; outside, she hadn’t breathed at all.