Here are the May question, at little late, but accounted for. Yes, Ifan, here is metric again.

The questions and answers for this poll were taken from Dennis Gravier's 100 Best Scuba Quizzes, Aqua Quest Publishing, NY.

Mike B
;)

A) Four feet (1.2 M)

If you inhale fully while lying on the bottom in water only four feet deep, hold your breath, and stand up, you could suffer a lung over expansion injury. Lung physiology and rapid pressure changes in the water are the reasons that avoiding breath holding is the number one rule of SCUBA diving.


Posting for Mike
as Mrs Scuba 101