[BBell]

These guys were in 225 feet of water. Would nitrogen be a problem that deep?

[Calvin Locke]

If I remember the decompression charts, developed from observations of healthy young male USN divers, btw, you can get away with a total "bottom" time, basically, under pressure, down to 190 feet, and back, without decomp stops, within 5 minutes.

They were probably using an O2-HE2 mixture.

Since two divers had problems, I'm guessing they bought the lithium CO2 removal canisters from El Cheapo Globalists Supply and Die Company.