You'd have to subtract about 1atm from that, but yes the sudden pressure change would be quite gross. That said, if divers are slowly "eased in" to the high pr

You'd have to subtract about 1atm from that, but yes the sudden pressure change would be quite gross. That said, if divers are slowly "eased in" to the high pressure environment, it is actually possible to equalize pressure slowly and acclimatize. Though 1.3km would still likely be beyond the limits of that https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5110125/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5110125/