Quote Originally Posted by Skipbreather  View Original Post
once I surfaced.

Not until discussing the dive during the 2 ½ hour ride home did we discover we both had begun to feel a bit “off” during the dive.
Dive specifics: Average depth 260 to 280 ft.
Hi,
this is the "first down gets to see the sharks syndrome"
Narcosis is dependant on descent speed. I used to fix the anchor on wrecks when diving in Brittany, which involved an as fast as possible descent, like less than one minute to -30 to 45 meters.
You get hit much harder than, e.g. you make an evaluating stop at -30m.

Some claim that you don't get hit harder, but the GABAA receptors which manage the transfer of ions at the synaptic gaps accommodate better when descending slowly.

regards,
Matthias