Major U.S. training agencies
mandate diving physicals and
medical clearances for divemasters,
assistant
instructors, and
instructors.
Entry-level
divers only need
to fill out a medical
questionnaire.
In Australia,
  however, the
  Queensland
  Territory has a legislative requirement
  for medical clearance for
  trainees, and nationally major
  training agencies encourage such
  medical clearance. Dr. Michael
  Bennett of the University of New
  South Wales Department of
  Diving and Hyperbaric Medicine
  acknowledges, “To their credit,
  the major dive training organizations
  have accepted such examinations
  as desirable throughout
  the country. It is standard practice
  that diving candidates are
  not accepted without medical
  clearance.” The South Pacific
  Underwater Medicine Society
  has published a standard medical
  form to guide physicians through
  examinations.
  
    | “Medical aspects of the sport should bemore closely regulated by some
 central, nongovernmental entity
 (Ernest Campbell, M.D.)
 | 
In 1969, the British Sub-Aqua
Club made medical examinations
for divers mandatory. They
required physicals of all applicants
and members, and these
became progressively more frequent
with age. A diver’s general
practitioner (GP) could conduct
these. In 1994, the Sub-Aqua
Association and Scottish Sub-
Aqua Club joined with BSAC to
form the UK Sport Diving
Medical Committee (UKSDMC),
which sets common standards for
all three diving organizations.
The UKSDMC found that examination
by a GP was largely
unhelpful in identifying divers with
significant medical conditions, so last
year it replaced the routine examination
with a
health questionnaire
the diver
completed. If a
diver answers “yes”
to any question,
he or she must
contact a medical
referee who may
pass the diver or, if
necessary, refer
him or her to a
specialist. Dr. Stephen Glen, UKSDMC
Chairman, told Undercurrent that the organization will publish
three-year safety statistics next year.
(PADI UK follows the same guidelines
as PADI America, the selfreport
medical questionnaire with
medical clearance required for “yes”
answers. It’s similar to what UKSDMC
members do.)
 Since 1990 in the United States,
  applicants for all levels of dive training
  are required to complete and
  sign a standard “Diver’s Medical
  Questionnaire.” Developed by the
  Undersea and Hyperbaric Medical Society (UHMS) and DAN; the
  form canvasses medical conditions
  that may affect safe scuba
  diving. A “yes” answer to any item
  means that the applicant must
  obtain written medical clearance
  to dive. Even then, not all students
  are accepted. However, as
  demonstrated in the case of the
  intoxicated 58--year-old woman
  completing the familiarization
  class, not all trainees are forthright
  about their health.
 PADI’s director of training
  and quality management, Brad
  Smith, told Undercurrent that, ultimately,
  the scuba instructor
  decides whom they will permit to
  take a scuba course. He or she
  may require anyone to secure
  medical approval from a physician,
  even if the student has
  marked “no” on all questions on
  the medical form.
 However, once certified, divers
  may dive forever with no further
  medical prohibitions unless they
  indicate problems on predive
  questionnaires. Should routine
  medical clearance be required?
 Ernest Campbell, M.D., (a.k.a.
  “Scubadoc”) told Undercurrent  that he feels strongly that “medical
  aspects of the sport should be
  more closely regulated by some
  central, nongovernmental entity
  possibly similar to the UK Sport
  Diving Medical Committee.
  However, this would require the
  total support of the training agencies
  and our quasi-official societies,
  as well as UHMS, DAN, and
  the recently formulated national
  boards. Getting physicians trained
  would be the easy part. Draconian
  rules would make it difficult by
  placing monetary, liability, and certification
  roadblocks.”
 UKSDMC medical officer John
  Betts is not so sure that getting
  trained physicians would be easy.
  He told Undercurrent that even if it
  is tempting to envisage mandatory
  medical examinations, it would be
  impossible to provide enough
  experienced diving doctors to cope
  with the numbers involved.
 While these are real issues, the
  overriding question is, “Would
  mandatory diving physicals for all
  recreational scuba significantly
  decrease morbidity and mortality?”
  They may not.
 A study in the British Journal of
  Sports Medicine (2000; 34:375-378)
  suggests that self-certification may
  be sufficient to keep medically
  related dive accidents to a minimum.
  It analyzed the routine physical
  examinations and self-certification
  questionnaire findings of
  2,962 Scottish divers. No examination
  finding alone caused a subject
  to be classified unfit to dive. One
  hundred and seventy-four subjects
  reported abnormalities and were
  referred to physicians. The most
  common reasons were assessment
  of asthma, hypertension, and obesity.
  Upon expert evaluation, they
  allowed most of the subjects to
  dive, with only 25 percent not
  receiving immediate clearance.
Even physicians trained in dive
  medicine may not be able to determine
  fitness to dive. A study reported
  in the Medical Journal of Australia  (1999; 171:595-598) sent fifteen
  hypothetical clinical scenarios to a
  group of physicians who had completed
  approved training in underwater
  medicine and asked them to
  declare the prospective scuba diver
  fit, unfit, fit after investigation, or to
  offer specialist referral. Seventy percent
  agreed about unfitness in four
  cases, and fitness in only two cases. For each case where the guidelines
  firmly indicated an unfitness to dive,
  at least one physician passed the hypothetical
  prospective diver. The study
  concluded, “There is no consensus
  among doctors who perform diving
  medical examinations about what
  constitutes fitness to dive; current
  guidelines need to be improved.”
 Joel Dovenbarger, vice president
  of medical services for DAN, says that
  few young persons entering scuba
  have worrisome health problems.
  The older population with longstanding
  health issues is by far the
  most problematic. In fact, more than
  half the diving deaths occur in the
  40-to-50--year-old groups.
  Cardiovascular disease, which is
  strongly age related, is the most common
  medical condition among those
  who die. Dovenberger maintains,
  “The responsibility for maintaining
  personal health remains with the individual,
  as well as the reassessment of
  fitness after illness, injury, or the
  effects of aging.”
 Major U.S. training agencies do
  promote medical prudence in their
  students and professionals. Without
  compelling evidence that diving physicals
  substantially reduce the risk of
  injuries and death, it is unlikely that
  the U.S. dive industry, a self-regulating
  and peer-reviewed entity, will mandate
  standards that increase the external
  costs of diving and reduce the pool of
  potential or active divers.
— Doc Vikingo