I was shopping around for some new tanks when I ran across this interesting toy at scubatoys.com In a nutshell, the CO Cop is a litmus test for carbon monoxide. I'm curious to know just how sensitive this thing is, but if it works, it's worth every penny.

If you haven't studied it before, Carbon Monoxide is one of those things you don't want in your air supply. Hemogloben (red blood cells) has a higher affinity for Carbon Monoxide than Oxygen. If there's enough CO in your air supply, you're body could become oxygen starved.

The main give away that a diver has CO in their air tank - aside from the dizziness, nausea, disorientation or convulsions - is a set of cherry red lips. That's right. If your dive buddy looks like he just put on some lipstick during the dive, double check him/her and end the dive.

Before I forget, the primary treatment for that (and most diving medical emergencies) is the administration of oxygen ASAP.