C
ontrolling buoyancy is a key component of your
diving safety. The physics of floating and sinking
are simple concepts, yet achieving practical control
of your buoyancy when outfitted with scuba
equipment and immersed in water is an entirely other matter.
Each change in equipment affects your buoyancy. As your
dive equipment grows more complex, the more attention your
buoyancy requires. Given its role as a fundamental element of
dive safety, it’s no wonder problems with buoyancy control are
often the underlying cause of a dive injury or fatality.
Divers with proper buoyancy control can maintain their
position with very little effort. They can descend or ascend
at will. In contrast, divers with poor buoyancy-control skills
struggle throughout the dive. In extreme situations, major
buoyancy-control issues may cause divers to make grave
errors such as descending well beyond their planned depth,
negatively affecting gas consumption and no-decompression
calculations, or on the flip side, uncontrolled ascents,
increasing the risk of decompression illness.
There is no doubt buoyancy control affects many aspects
of dive safety. Experts in dive training, dive medicine and
research all know just how integral it is and are always eager
to share thoughts on how to develop and maintain good skills.
Training
Good buoyancy begins with proper weighting. It is imperative
the amount of weight you use allows you to descend, not
causes you to do so. Weight placement makes a difference,
too. A classic buoyancy-control device (BCD) is generally
configured to require a separate weight belt, whereas newer
BCDs often integrate the weights. Each approach affects
a diver’s body position in the water, requiring time and
attention to get comfortable. Using rental gear can complicate
the process, especially for new divers, as each change in
configuration, responsiveness and other variables can alter a
diver’s comfort and buoyancy. Diving with a drysuit, a weight
harness or a rebreather adds to the complexity.
The BCD is the most complex piece of scuba equipment a
diver must master. To truly master buoyancy control, a diver
must understand his BCD inside and out, including knowing
how it reacts to the addition or venting of air. It requires
proper maintenance (see “Gear,” Alert Diver, Spring 2011) to
prevent sticking buttons or leaking bladders. Malfunctioning
BCDs can lead to uncontrolled ascents or descents before
a diver even realizes what’s happening. Like any piece of
equipment, proper function requires proper maintenance.
But lack of maintenance is not the only concern; operator
error can also cause loss of control. Improperly connecting a
low pressure inflator can cause negative buoyancy without a
means to correct it. Hitting the inflator button instead of the
vent button can cause a rapid ascent. Every diver needs to
be familiar with his own equipment as well as his buddy’s. In
a stressful or emergency situation there may not be time to
search for weight releases or inflator/deflator valves.
Diving Medicine
Many do not equate buoyancy skills with dive medicine,
but there is definitely a connection. The most common dive
injury is consistently middle-ear barotrauma. There are
certainly many factors that lead to this injury, but buoyancy
issues are often among them. Every diver is taught that if
discomfort is felt during descent to stop the descent, ascend
a few feet or until the discomfort resolves, and then attempt
to equalize again. This is very difficult to execute without
good buoyancy control. When experiencing a reverse block
during ascent, a diver should stop the ascent, descend until
the discomfort resolves and attempt ascent again using
appropriate equalization maneuvers. The ability to stabilize
and adjust position in the water column certainly takes
practice, but as a cornerstone skill, it’s worth the effort.
Most marine life injuries are due to incidental contact. Proper
buoyancy helps divers avoid contact as it maintains necessary
distance from marine life. It also prevents the destruction of the
reef and the microscopic critters that live on subaquatic surfaces,
as buoyancy control reduces the need to place hands on those
surfaces to steady a diver’s position. Buoyancy skills not only
protect divers but the environment as well.
Finally, one of the most serious consequences of inadequate
buoyancy control is a rapid ascent. This can place a diver at risk
for a lung overexpansion injury (pulmonary barotrauma), and it
The Importance of
Buoyancy Control
Never ignore this safety cornerstone.
B y M a r t y M
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