Diving and hookahs
 

He knows just enough to be dangerous. Truer words were never spoken. Thank you Bushwacker. I cough cough finally got certified {for diving} last summer. It is school and you get enough to be smarter about your choices. It is, in some ways, like drivers ed.,just enough to be an insurance risk. Much like a pilot with 100 hours, you are most at risk.

The Kevorkian contraption had some benefits I was not aware of and some that frightened
the learned. 110 v and saltwater come to mind. I came across this little tomb and thought it most comprehensive and informative.

http://www.keeneeng.com/pamphlets/introHooka.html

That would be a tome, not a tomb. One you read, the other is for dead bodies. :)

Somewhere an English teacher is rolling in a tomb.