TAKE HOME TIPS FOR FREEDIVER SAFETY
Always remove your snorkel from mouth
when freediving |
- On returning to the surface, blast clearing your snorkel
is very difficult and could lead to SWB if a diver is low on air - Keeping the snorkel in your mouth can complicate equalization at depth - When low on oxygen the diaphragm begins to contract and the snorkel can allow inhalation of water into the lungs - Should a diver suffer a SWB, a snorkel in the mouth makes it difficult to open the airway to administer CPR. When the divers body and vocal cords relax the snorkel can act as a tube, funneling water right into the diver’s lungs. |
| Never exhale underwater or forcefully upon surfacing | - Exhalation on decent can cause early problems with equalization - On ascent it causes loss of buoyancy which requires more effort from the diver and can lead to SWB -As you ascend your lungs are rapidly expanding, pulling the remaining oxygen in your blood to your lungs, heart and brain. If you exhale you are speeding up this process, increasing your risk of SWB. - Taking a large, sudden breath upon surfacing causes your oxygen level
to rapidly increase. This tells your brain that you have enough or too
much oxygen therefore lowering blood pressure and carbon dioxide levels,
causing the brain to momentarily shut down causing a blackout. |
| Stick to proper surface intervals | - Proper surface intervals are important because they allows time for
your body to flush out carbon dioxide and help metabolize the accumulated
lactic acid that your muscles generate during a dive -As a general rule, a surface interval should be double the total time spent underwater i.e. if your dive was one and one-half minutes you need three minutes of down time to rest and recover. After that down time you can then begin preparing for the next dive. - For dives over 60 feet, your surface intervals should increase to
5-10 minutes for each minute spent underwater |
| Never hyperventilate | - Hyperventilation is dangerous because the effects are unpredictable
from diver to diver, and even in the same diver from day to day and from
hour to hour - Hyperventilation causes some central nervous system changes, decreased blood flow to the brain, dizziness, tingling and muscle cramping in the arms and legs -Expelling too much carbon dioxide, caused by hyperventilation, will
also cause a state of euphoria and well-being. This can lead to over
confidence and the dramatic consequence of a body performing too long
without a breath: blackout |
| Never dive alone and know the abilities of your buddy | - Both you and your buddy should be fully trained in rescue techniques
and CPR
- Buddy should meet you FACE TO FACE at about 15 feet and visually
- Buddy should know what to look for in a SWB i.e. the attitude and angle of divers path as they ascend, if diver is exhaling on ascent, color of divers lips, if diver has arched back, spread arms, dropped gear, or is sinking. * Note: Unconscious divers may continue to kick or swim because the muscles in arms and legs can function for short periods with less oxygen than the brain - Buddy must always get a verbal okay from diver after surfacing and make sure they are breathing and mentally alert before buddy should begin diving -Your buddy must be attentive and capable. This is important as to
not cause a double or triple fatality by the rescue freedivers over-extending
their capabilities in an attempt to recover the primary victim. |
| Never dive at the same time as your buddy | - Obviously rescue is impossible if you are both at risk of SWB |
| Make a dive plan and stick to it | - Decide who is doing safety for whom and when -What to do in an
emergency: make a plan BEFORE an emergency happens. Don’t assume
you and your buddy ‘just know’ what to do |
| Never freedive after SCUBA | - Wait at least 12 hours after SCUBA diving before you freedive. -
The Nitrogen remaining in the tissues after SCUBA diving can lead to
decompression sickness (the Bends) when micro-bubbles are recompressed
on a freedive and expand upon the rapid ascent of a freedive |
| Never ‘push’ your ear drums | - A burst eardrum will cause extreme vertigo, dizziness and nausea - Equalize on decent only - Never force an equalization - Never continue a dive after a failed equalization- abort dive! |
| Always be correctly weighted | - If you choose to wear a weight belt, weight yourself so that you float at 15 feet. Your chances of recovery are greatly complicated if you sink |
| Review sea conditions and take them into consideration | - Sea conditions will affect the dive and safety, i.e. current, visibility, water temperature, swell, distance from boat and surface traffic. More current, more exertion etc… |
| Use only one gun per two divers while spearfishing | - With one gun between two divers there is less temptation to be diving
at the same time, and it allows one diver to fight the fish from the surface
relieving the diver that has been underwater - Ideally there should
be three divers, one shoots the gun, one fights the fish from the surface
and one spots the diver who shot the gun |
| Don’t hyper extend you neck on decent or ascent | - Neck extension will cause difficulty in equalization on decent. On divers ascent it can affect necessary blood flow to the brain and increase pressure in the area of the baro-receptors in the neck sending the wrong message to the central nervous system which may increase pulse rate |
| Keep a constant pace on ascent; no bursts of energy towards surface | - Economy of movement is essential to conserve oxygen and keep the pulse rate low. If you do not remain patient and calm you will panic and use up all your remaining oxygen causing SWB. A constant pace must be preserved throughout the ascent despite the lactic acid build up or ‘burn’ in you legs |
| No diving after a ‘Samba’, blackout, or if the diver has cyanosis (blue lips) | - Any loss of motor control such as: shakes, tunnel vision, starry vision,
momentary memory loss, tingly or a burning sensation in legs and arms
(Sambas) means that the diver has missed SWB by the narrowest of margins.
This should be considered a near-death experience and the dive should
be examined for mistakes and corrected. - The above symptoms or any
loss of consciousness should be the end of diving that day for that
diver |
| Never dive when tired or cold, hung-over or while under the influence of any substance | - Being cold, tired, using drugs or alcohol all impair judgment and
breath-hold ability and predispose a diver to SWB - One of the first
symptoms of hypothermia is tiredness, as soon as you feel cold or tired
your breath-hold ability is already compromised, do NOT underestimate
the consequences of this |
| Stay very well hydrated | - You become dehydrated easily while freediving because of increased
production of urine and expelling huge quantities of water during ventilation
- Water should be present on every dive trip and divers should be encouraged
to drink it. Dehydration vastly increases the risk of SWB and severely
compounds equalization problems |
| Don’t eat right before diving | -It is recommended to wait 2-4 hours after eating before you begin freediving. A large volume of blood that could be carrying oxygen to the brain is being diverted to the digestive system |
| KNOW AND RESPECT YOUR LIMITS! | - DEEP is relative – it may mean 20 feet for some and 80 feet
for others - Be in tune with your body and self at all times and know when to back off and call it a day - If you have a ‘gut feeling’ or any apprehension about
the depth…don’t do it |