regulator free flows: this is certainly a better situation than a regulator that won't deliver air! you should tilt the regulator so the air bubbles can flow into your mouth while quickly pressing the purge. if pressing the purge doesn't stop the free flow, you should safely make an ascent and take your regulator for service.
regulator fails / out of air: if your equipment fails to deliver air, or you are truly out of air, you should quickly assess the situation. if your buddy is near, you should signal 'out of air' and use his/her alternate air source while you make a safe ascent. if your buddy is not near, you should make a controlled ascent by always exhaling and keeping your airway open to avoid lung over-expansion.
mask
flooding: this is an easy problem to solve. the most important thing
to remember is not to panic and keep the regulator in your mouth, simply
tilt your head backwards while gently exhaling out of your nose to clear
the water out.
uncontrolled ascent: this can put you at risk for an embalism caused by nitogen loading at depth or lung over-expansion. it is important to keep your bcd deflated (yank the dump valve) since air expands as you ascend. it is crucial to always exhale and keep your airways open so the air in your lungs does not expand and pop your lungs like a balloon. finally, it is best to spread your body out as much as possible to try to slow the ascent.
uncontrolled
descent: this is much less common. a diver should always remember
to ditch their weights or heavy equipment in an emergency situation. every
diver has heard horror stories of victims found at the bottom with a full
tank of air and a weight belt. a weight belt is a small investment in
comparison
equalizing: there are various methods for equalizing ear pressure during descent. an easy method is holding your nose when you feel your ears start to 'squeeze' and gently exhale. some divers (like me!) can simply wriggle their muscles to open the eustation tubes. if you do have an equalization problem, you should stop, briefly ascend until your ears are clear, and then try again.
the
biggest marine encounter fear is no doubt the great white shark. monterey
is at the southern end of a 120 mile stretch of california coast known
as the 'red traingle', there have been a number of attacks in the area,
including some on divers.
sharks more commonly attack people on the surface (their favored feeding zones), so you may want to minimize surface and mid-water swims. sharks do feed on seals / sea lions, so you may also want to avoid diving in areas where these are especially plentiful, like the farallon islands or ano nuevo.
spearfishermen should be aware that bleeding, injured fish do attract predators so they should be removed from the water as quickly as possible.
