quick question

[Thalassamania]

Sorry that was a stupid oversight:

You are all forgetting about bubble pumping and I can point to several people who have injured themselves by freediving after scuba diving. Bad, bad, juju.

Yes indeed. To be honest until reading up more on freediving recently I didn't realise that it wasn't advisable to freedive during the surface interval between scuba dives.

What is bubble pumping? What kind of injuries were sustained? A form of DCS?

When you dive you supersaturate with nitrogen. On ascent you bubble venous side where your BP is lower. These bubbles are filtered out by the capillary beds of your lungs and that gas ultimately escapes to the atmosphere. If you resubmerge while you have these bubbles in your lungs you run the risk of compressing them and having them move through the capillary bed into the arterial circulation. If you now ascend these bubble can grow while in the arteries where they are traveling in a network of ever decreasing size vessels. Such vessels can become plugged with air with effects very much like DCS or even AGE.

I still have not found the DAN issue but I remember that the low down of it was pretty much what Thalassamania is writing here so don't do it