I agree 100% with Keith--every one who dives with any compressed gas should have a Scuba course. In fact I might expand on that by saying anyone who does even free diving should take a diving Course (and I don't mean a 2 hour course at a resort). Scott is in a catch 22 because of a physical disability. This is why I suggested a consultation to see what his lung function is. He should not take a course until he has a physicians clearance. Back in the 60's we had a problem with diving "certification" where there were not standards--and because of this we saw frequent deaths at Catalina Island. The standards were increased with PADI and NAUI courses and the mortality decreased. Both NOAA and the military services have rigid physical requirements--and have certified dive medical officers. PADI has a medical questionaire which is filled out: http://www.my-town.com/learn2dive/Medical.pdf: This has an excellent bibliogrpahy. As Keith notes DANS has: specifics on their web site and consultant physicians: This is affiliated with Duke college of Medicine. http://www.diversalertnetwork.org/medical/index.asp The Undersea and Hyperbaric Medical Society web site is: http://www.uhms.org/ There is board certification in Undersea and Hyperbaric Medicine. I began free diving at age 9 and soon was diving to 40 feet--a depth where even with free diving there are some risks. My first "compressed gas" diving was at a YMCA Camp where we had a diving helment which fit on the shoulders and wore lead shoes. Two fellow campers had large diameter hand pumps and a rope translated signals. Probably risky behavior! Agree with Keith's assesment of DANS--excellent resource. However the 80 feet of hose will not work to go to 40 feet--the limit if pressure in a regulator of a small compressor is slightly less than one atmosphere (33 feet)--but the risks are real. Bob Austin