[ADR]

I think it was in the PFI course that they said don't blow your nose but sniff it back and then spit out the mucus. Blowing can shoot the mucus into the eustacian tubes and block them due to the positive pressure when blowing. I always feel the gunk comes loose after a few dives and the need to clear it and blowing sometimes caused the blockage problem for me. Since moving to sniffing it back and spitting the gunk out I haven't had this problem....touch wood!