Training courses for scuba divers were branded as
“madness” by scuba experts in early August as a coroner
heard how three divers died in separate accidents
off the British coast.
Dr. Philip Bryson said he was amazed that divers
  could call themselves “advanced” after fewer than 10
  sessions in open water. He singled out PADI for particular
  criticism. He said its methods had forced others to
  streamline their training programs. 
Bryson, head of the Diving Diseases Research
  Centre, said: “People want to be advanced divers. They
  want that certificate and they are willing to pay for it.
  We have people presently in diving who feel they are
  advanced but have no experience whatsoever. The diving
  community needs to be totally re-educated.”  
A police diver, Peter Tapper, told the hearing that
  “the process moves far too quickly because there is
  an element of money.” Concerns are mounting that
  the certificates are too easy to obtain and that some
  divers are being caught up in the rugged conditions
  around the U.K. after learning to dive in the less harsh
  Mediterranean or Caribbean.  
Mark Jackson, 41, who died last year, had learned to
  dive in the Mediterranean and had limited experience.
  He embolized. His diving buddy, who ran short of air,
  had made only a handful of dives and was frightened
  and disorientated because she had never come across
  currents and swells before. Jackson had seen his doctor
  about high blood pressure, obesity, asthma, and
  depression — but declared none of these on his PADI
  medical form. He had drunk a bottle of wine and several
  vodkas the night before and had complained of
  sweatiness and indigestion just before the dive.  
Novice diver Albert Tythecott, 65, died in June,
  after coming to the surface too quickly from 21 meters.
  Christopher Sidgwick, 40, was wreck diving with friends.
  He became confused and breathed from his smaller
  back-up tank — which was empty when he was brought
  to the surface — rather than his main tank that
  remained full. He had completed a wreck-diving course
  at a lake two weeks before.  
Bryson said British training agencies had to streamline
  their courses to compete with PADI. He said:
  “PADI has brought that reduction in training down and
  they claim they have done it with valid data and that
  there are very few problems. Other U.K.-based diving
  groups that had longer training regimes have had to
  come into line. “I do not believe that someone with
  eight dives should be classified as an advanced diver.
  That is madness, end of conversation.”  
In fact, the minimum number of open water dives
  for an advanced open water certificate is nine. Mark
  Caney, a PADI VP, said the system was tried and tested.
  “We have a lot of data about the efficacy of our system
  and the vast majority are out there diving quite happily.
  But accidents do occur. In nearly every case, there is at
  least one instance where a main diving rule was flouted
  and that is nearly always the cause of the accident.”  
From an article in the Guardian, August 9, by Steven
  Morris, BBC reports, and other sources.