SAFETY ONARCHAEOLOGICAL SITES UNDERWATER AND ON THE FORESHORE 41
can lead to divers becoming cold. It is advisable to use more
insulation than would be used for a normal dive; altern-
atively shorter dives can be considered. The extent to
which efficiency deteriorates as the diver becomes chilled
and the safety problems associated with cold are well
known. Clearly, there is nothing at all to be gained from
allowing divers to become colder than is absolutely
necessary.
It should not be forgotten that there are equally
serious problems associated with divers and even surface
crew becoming over heated (hyperthermia), which can
result in dehydration. Divers can be tempted to spend long
periods in diving suits, maybe waiting for their next dive,
filling in logs or washing finds. Divers should be aware
that dehydration could also exacerbate decompression
problems.
Diving supervisors should assess all the factors that might
be associated with a particular site and take measures to
avoid any of them becoming a problem (see risk assess-
ment). It should also be stressed that the diving supervisor
should have the authority to restrict any diver (even the
director) from diving if, in his/her opinion, the diver is
unfit to do so, for whatever reason. It is advisable dur-
ing intense projects involving long, continuous diving
periods that divers are encouraged to take scheduled
non-diving days to recover and reduce the risks associated
with residual nitrogen build-up. A non-diving day can
enable divers to catch up with paperwork and help with
surface tasks.
As the sport of diving has developed, new and more
complex diving systems are becoming popular, particu-
larly enriched air (nitrox), trimix and re-breathers. These
systems can offer distinct advantages to the archaeolo-
gical diver, such as extended no-stop times, safety buffers
and clarity of thought associated with some breathing
mixtures, which is an important factor in achieving high
standards of archaeological work. However, there can be
associated technical and logistical problems that need
to be considered. It is important that those responsible
for the diving-related aspects of a project consider the
benefits of all available diving systems. Whichever one is
chosen, it is equally relevant to go through the process of
risk assessment and put in place appropriate safety meas-
ures and codes of practice.
Psychological problems: There are a number of factors
that can have an impact on a diver’s ability to make
decisions effectively under water. The effects of nitrogen
narcosis are well known but there are other things that
can have similar effects, such as anxiety, stress, alcohol/
drugs and even over-enthusiasm. Some of these factors
can result in a disregard for personal safety, while others
(e.g. anxiety) can result in panic and an abandonment
of proper diving practices. In extreme cases, it has been
known for divers to suddenly rush for the surface, even
though their training would tell them that this is poten-
tially dangerous. Any impairment in the ability to make
good decisions will affect safety and the standard of
archaeological work. It is therefore important to consider
taking measures that will alleviate these problems, such
as communications, which make it unnecessary for the
diver to remember detail or measurements. Using an
alternative breathing-gas, as discussed above, is also an
option. A combination of training, experience, common
sense and an appropriate and well-maintained diving
system will help prevent many of the consequences
associated with psychological problems.Diving techniques: Sport-diving training should be
adequate for allowing a diver to operate safely within most
projects, but there are some aspects of underwater work
which are not covered in sport-diver training. Some of these
may even run contrary to the normal diving practices
taught to recreational divers.
The advantages of neutral buoyancy are rightly em-
phasised in terms of sport-diving and good buoyancy
control is at a premium when engaged in photography
or the investigation of a delicate deposit. However, to
be effective, some tasks and environments require the
diver to be negatively buoyant while actually working.
On occasions, provided it is within the code of practice
in use and prevailing environmental conditions allow it,
divers may also find it easier to remove their fins when
working. This can help to avoid accidental damage to
archaeological material and often increases the comfort
of a diver when supported by a grid.
Similarly, diving with a partner is a mainstay of safe
sport-diving, but this is not always possible or practical
in a working situation and alternative safety procedures
will need to be implemented. It is possible to draw a
distinction between diving alone and working alone with
other divers in the vicinity, but this must take into
account all local site conditions and the experience of the
diving team.
Diving alone can have its advantages – for example,
in very poor conditions where the presence of a buddy
diver would impede the working diver, or where the task
only requires one diver and the buddy would be ignored
and effectively be diving alone. Lone divers must have
an effective means of communication with their surface
team and be competent to use the equipment (e.g. lifeline,
hard-wire or through-water communications). There
should also be other team members who will be respons-
ible for tending the diver’s lifeline, a stand-by diver
ready to provide assistance and a dive supervisor. Many
countries have specific regulations that govern archae-
ological diving practice, which can provide useful
guidance for those divers not at work.