Jellyfish Stings – Facts, Treatments, and Remedies

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By Natalie Gibb
  Scuba Diving Expert

How dangerous can a gelatinous sac of straggly tentacles be? A jellyfish’s soft, transparent body appears vulnerable to all sort of prey, and a diver may be surprised that a jellyfish can survive to grow to maturity without being eaten. Yet, a jellyfish’s delicate body is anything but unprotected. The tentacles of a jellyfish contain uncountable numbers of stinging cells, called nematocysts, which effectively protect it from many potential predators and are used to stun small prey.

Depending upon the species of jellyfish, contact with the stinging cells can injure, or even kill a human being. But how much of a threat are jellyfish to scuba divers?

Are You Likely To Be Stung by a Jellyfish While Scuba Diving?:

No. Jellyfish are not a major threat to scuba divers. The majority of jellyfish species tend to stay near the surface of the water, and are more of a threat to swimmers and beach-goers than they are to divers. In addition, a jellyfish must contact a person’s bare skin in order to sting. Generally, divers wear wetsuits or dive skins and have little exposed skin to sting.

Dive guides and local dive centers will usually alert divers if dangerous species are present. If a diver spots a jellyfish underwater, he should take care to stay at least a few meters away. Some species of jellyfish have transparent tentacles over one meter in length which may be difficult or impossible to see underwater.

Are Jellyfish Stings Dangerous?:

The effects of jellyfish stings can range from mild pain and stinging, to skin irritations and blisters, to respiratory problems, cardiac arrest, and death.

The toxicity of a jellyfish sting depends upon the species of jellyfish and the reaction of a person’s body to the jellyfish venom.

The most toxic type of jellyfish is the Box Jellyfish (Chironex fleckeri and Caruka barnesi) found in Australia and some regions of the Indo-Pacific. The venom of the Box Jellyfish has been known to kill a person in five minutes.

People react differently to jellyfish stings. Consider a jellyfish sting as a “dose” of poison. The smaller the person, the greater the effect of a jellyfish sting will be. Just as some people are highly allergic to bees and may go into anaphylactic shock from a single sting, other people may be unusually sensitive to jellyfish venom and may have a similar severe reaction.

How Should a Diver Treat a Jellyfish Sting?:

box-jellyfish

Most diving safety organizations recommend vinegar as immediate first aide for a jellyfish sting. Vinegar, which neutralizes a jellyfish’s stinging cells, has two primary benefits – to minimize pain and discomfort, and to stop the delivery of jellyfish venom. When stung by a jellyfish with exceptionally toxic venom, such as that of the Box Jellyfish, the immediate application of vinegar to neutralize stinging cells and prevent more venom from entering a diver’s body may be the difference between life and death. Vinegar should be in every dive boat’s first aid kit. If vinegar is not available, a paste of baking soda may be used to neutralize sting cells. Salt water may be used as an additional rinsing agent if necessary.

In no circumstances should fresh water be applied to a jellyfish sting as fresh water may cause additional stinging cells to fire. Urinating on jellyfish stings is not recommended to neutralize jellyfish venom (sorry).

Jellyfish tentacles tend to stick to a diver’s skin and must be removed once the stinging cells are neutralized. Shaving affected area with a razor has proven very effective in removing tentacles. Other suggestions include using tweezers or thick gloves to pry the jellyfish tentacles away. Any abrasive material, such as sand, may be used to scour the sting area when other methods are not available.

Cold and hot packs (as long as they are completely dry) may be used to alleviate the pain of a jellyfish sting. Most doctors recommend hydrocortisone cream to be applied topically to the stung area.

The victim of a jellyfish sting should be monitored carefully for signs of shock, difficulty breathing, nausea, and other signs of severe allergic reactions. If any allergic reaction is suspected, be sure to contact a doctor immediately.

Conclusion

In most cases, an encounter with a jellyfish while scuba diving is anything but dangerous. Jellyfish are among some of the oceans most surprising and fascinating creatures, and it is enchanting to watch their pulsating movements as the drift through the water. Enjoy your jellyfish encounters, just make sure to give them plenty of space!

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Mask Squeeze in Scuba Diving – By Natalie Gibb Scuba Diving Expert

Mask

Have you ever surfaced from a scuba dive with an indentation from your mask on your face? If so, you may have already experienced a mild mask squeeze.

Mask Squeeze is the condition that occurs due to incorrect equalization of the air pressure inside the mask causing the outside pressure at depth to push the scuba mask to a divers face resulting in bursting of the small blood vessels around the eyes.

Serious mask squeezes are rare in scuba diving, but when they do happen, they can be painful and horrifying to look at.

Thankfully, mask squeezes are completely preventable.

What Causes a Mask Squeeze in Scuba Diving?:

A diver’s mask traps a pocket of air against his face . During descent, the air trapped behind the diver’s mask behaves in the same manner as the air trapped in his other body air spaces. As a diver goes down, the pressure surrounding him increases with his depth. The increase in pressure causes the air in his mask and other body air spaces to compress in accordance with Boyle’s Law.

As the air compresses, it creates a pressure vacuum, or suction, on the diver’s face.

If the situation is not remedied, the suction can be so forceful that it damages the diver’s facial tissues and eyes.

 

How to Identify a Mask Squeeze:

Mask squeeze affects a diver’s eyes, cheeks, and forehead.

A diver with severe mask squeeze may have inflammation and raccoon-like bruises over his cheeks and surrounding his eyes.

Mask squeeze may also cause subconjunctival hemorrhages, or bleeding under the thin layer of transparent tissue covering the whites of the eyes.

A diver who has experienced a mask squeeze may have bright red blood spots in the white of his eyes. His eyeballs may even be completely red (like a zombie!).

 

Equalizing a Scuba Mask to Prevent a Squeeze:

Preventing a mask squeeze is simple.

A diver need only equalize the pressure in his mask as he descends by adding air to the mask’s air space.

To do this, a diver exhales into the mask from his nose, much as he would when clearing his mask of water. Many divers exhale small amounts of air through their noses without realizing it as part of their normal breathing cycle. These divers will not need to take any additional steps to equalize their masks.

However, divers who have mastered “mouth only” scuba breathing will need to exhale into their masks periodically during descent. A diver should equalize his mask air space anytime he feels a slight suction on his face from his mask. Of course, it is best to prevent any pressure build up whatsoever, so a good rule of thumb is to exhale into the mask after each ear equalization.

No special action need be taken to equalize a scuba mask during ascent. The air inside a diver’s mask will expand, just as the air in his other body air spaces. The expanding air will simply bubble out from under the skirt of the diver’s mask, and does not present a problem.

Is Mask Squeeze Dangerous? What Is the Treatment?:

Mask squeeze is not usually dangerous and does not cause permanent damage.

It is uncomfortable and embarrassing.

Divers who experience a major mask squeeze, particularly a mask squeeze involving the eyes, should seek the advice of a doctor familiar with hyperbaric medicine. Antibiotic drops may be recommended for the eyes to prevent infection. A diver with an eye squeeze should expect the bright red colour to slowly fade to green or yellow before disappearing, just as any other bruise would do.

“Save a Dive” Kit

SaveaDiveKit

 

Save a dive kits may be a small as a zip-lock bag or as big as a tool box, a diver’s save a dive kit will differ depending upon his needs and type of diving.

Suggested parts for the Basic Save a Dive Kit:

Spare mask strap
Mask straps are one of the most common items to break before a dive. Be sure to select a spare mask strap that fits your mask.

Spare fin strap and buckle
Fin straps break less frequently than mask straps, but they do break.  Be sure to choose the correct strap for you fins.

Spare regulator mouthpiece and zip tie/cable tie to secure it.

A spare regulator mouthpiece is an absolute essential.

Basic o-ring kit
This should include o-rings for low pressure and high pressure hoses, as well as o-rings for yoke tank valves or o-rings for DIN regulators (depending upon which you use).

High pressure and low pressure port plugs for the regulator first stage.

When a diver removes a hose from his regulator first stage, he must plug the hole with a port plug. Bring along both a high pressure and low pressure port plug that fits your first stage (apex first stages have unusually large port plugs).

Small adjustable crescent wrench
This is used to remove hoses from the regulator to replace o-rings.

Hex wrenches/ allen keys
Hex wrenches are used to remove port plugs, as well as for a variety of other applications.

Cutting device/knife
At a minimum, your cutting tool should be able to cleanly slice off zip ties and snip strings and bungee.

Needle nose pliers
Needle nose pliers are great for just about everything that needs to be pulled or tightened.

Small pot of silicon lubricant

This is used for greasing o-rings in dive gear, dive lights, etc.

A lighter

Zip ties and duct tape

Nail clippers

Nail clippers are useful for nipping of zip ties and clipping small items.

White trash bag.
Use a white plastic trash bag as a work surface on dirty or wet areas. This makes seeing o-rings and parts easier, and keeps them clean and dry.

Dry suit zipper wax.

Essential if you use a dry suit.

A DIN-to-yoke or yoke-to-DIN adaptor

This allows you to dive with both DIN and yoke tanks.

• Bungee/ Shock Cord

Bungee can be used to secure lights, create necklaces for back-up regs (long hose configuration), manufacture watch/computer straps, and create octopus/alternate air source holders.

 

 

 

Do I Need to Be a Good Swimmer to Scuba Dive?

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Participation in a high school swim team is not a prerequisite for scuba certification. Scuba certification swim tests are not timed, and participants can use whatever swimming stroke they desire to pass the test – even goofy ones.

Should All Scuba Divers Be Able to Swim?

This is certainly an interesting question.

People enrol in scuba courses for a variety of reasons. Some state that they want to learn to dive in order to overcome a fear of the water or to learn to swim. I would urge such people to become comfortable in the water by enrolling in swimming courses before ever considering a scuba experience program or entry-level certification.

Diver Confidence:Swim1

While the technique of swimming underwater in scuba gear is very different from the technique of swimming on the surface without equipment, confidence in oneself and one’s abilities in the water does translate to diving.

In many cases, this confidence and ability appear to be directly correlated with a student’s comfort level when scuba diving. Students who are completely certain that they would be able to survive in the water with out scuba gear are certainly much more comfortable using it.

• Basic Diving Skills:

Consider that even a scuba program that does not include a swim test will still require the student to put water in his mask and to remove a regulator underwater.

Students who are afraid of having water in their faces will not enjoy these skills, and would do better to increase their comfort level in the water before attempting to dive.

• Problem Solving:

Scuba diving is an equipment dependent activity, and the reliability of the equipment is extremely high.

However, the remote possibility exists that a diver will need to deal with an equipment-related issue by using emergency management skills such as switching to another regulator, even during an initial dive experience.

Scuba divers do not need to be expert swimmers, but a basic ability to handle oneself in the water without fear or stress is an absolute requirement in my opinion.

Knowing how to swim and float are a huge step in acquiring that confidence. Prospective divers who do not have the ability to stay calm on the surface without a floatation device or who cannot swim (however sloppily) for a short distance should first learn these skills with a professional swimming coach.

A diver who is not confident without his gear is one uncomfortable situation away from panic, and panic, as all scuba divers know, endangers both the person panicking and those around him.

Although knowing how to swim is not required for basic scuba experience programs, it is advisable.

The Art of Equipment Configuration

Diver 1

1. Accessibility:

The single most important concept in scuba equipment configuration is accessibility. A diver should be able to deploy, use, and stow dive gear easily and efficiently. Any configuration that makes accessing a piece of dive gear difficult or complicated should be re-thought, even if it fulfils all the other tenets of optimized equipment placement. Whenever possible, configure all dive gear so that it may be deployed and operated with one hand. This ensures that a diver can use his other hand for emergency management, such as maintaining physical contact with an out-of-air buddy.

2. Durability:

The manner in which a diver configures his gear should ensure that it will stay in place for an entire dive. A common equipment configuration failure is the alternate air source regulator coming free of its quick release.  The first time a piece of gear comes loose, the diver should reconfigure his gear to prevent the problem from reoccurring.

If it happened once, it will happen again!

3. Streamlining:

All dive gear, including accessories and hoses should be streamlined. In no circumstance should a piece of dive gear dangle more than a few inches below a diver’s horizontal body line . Hoses should be adjusted so that they do not loop above or beside the diver. Keep in mind that regulator hoses are available in a variety of lengths. Proper streamlining reduces the chance of entanglement, damage to the environment, and drag.

A common failure of streamlining in standard recreational scuba diving is the octopus-style alternate air source, which necessarily must be attached to a longer hose to facilitate donation to an out-of-air diver. The hoses on octopus-style regulators typically loop out to the side of the diver, presenting an entanglement hazard and creating drag. As far as streamlining goes, integrated alternate air sources and long hose/necklace regulator configurations are both preferable.

All types of diving require some level of redundancy in the gear. Recreational open water diving requires that a diver carry at least one redundant second stage for his buddy to use in an emergency. More advanced or technical types of diving may require additional redundant gear for safety. A diver should carry the minimum amount of accessories and gear that allows him to dive safely. At a certain point, additional gear no longer increases dive safety. The trick is to balance redundancy and simplicity when configuring dive gear.

5. Trim and Comfort:

Once a diver has optimized his equipment configuration, he should test it in a forgiving environment such as a pool or shallow water dive site. When evaluating changes to his gear configuration, a diver should notice whether the changes upset or improve his trim and whether or not position of the gear is comfortable. No matter how fantastic it seems on the surface, the final test of an equipment configuration is whether or not it is comfortable and functional underwater.

Evaluating and adjusting your scuba diving equipment configuration can make diving easier, safer, and more comfortable.

What to Expect on Your First Scuba Dive

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Scuba Diving Takes a Little Getting Used to . . . But It’s Worth the Effort!

Some divers take to scuba diving like fish underwater. They put regulators in their mouths and off they swim! However, this is the exception rather than the rule.

For most new divers, scuba diving feels a little strange at first. Be patient with yourself, don’t rush through skills, and take your time. By the end of your first dive you will already feel exponentially more comfortable underwater than you did when you first entered the water

Scuba Courses Are Taught in “Baby Steps”

New scuba divers are not expected throw on a full set of scuba gear and leap off a boat into the deep blue sea on their first scuba dive. A dive student’s first dive will be at a controlled dive site such as a pool or shallow bay. At least one area of the dive site will be shallow enough to stand up in. What’s more, before ever entering the water, a scuba instructor will explain to new divers how all the dive gear work, and will familiarize them with simple techniques used to dive safely. The first skill you are likely to try is breathing through a scuba regulator with just your face in the water

Breathing Through a Scuba Regulator:

Breathing through a scuba regulator for the first time can feel strange. The act of breathing itself, especially in very shallow water, feels almost exactly like breathing in the air. The aspect of breathing through a regulator that is disconcerting is that a student is required to put his face in the water and inhale. This is not a typical human behaviour, and it is completely normal to be a little hesitant to put your face in the water and inhale at the beginning.

The most important thing is to exhale fully after each breath. This prevents divers from hyperventilating and feeling starved for air. Some students adjust to regulator breathing after just a few breaths, while others take longer to gain confidence in their scuba equipment. Take your time! Be comfortable with breathing at the surface before descending into the water.

The Noisy Underwater Environment:scuba_gear

Divers who have done research into scuba diving have probably read about the silent, relaxing underwater world. This is not completely accurate. Breathing underwater is surprisingly noisy! Once a diver becomes accustomed to breathing underwater, he starts to tune out the bubbling sound of exhalation and the comforting whoosh of air as he inhales, but at the beginning, the sounds are surprisingly loud!

Water conducts sounds much more efficiently than air does because of its density. Sound waves travel more quickly in water, and reach each of diver’s ears almost simultaneously. Pinpointing the origin of a sound is difficult, as the physics of sound wave transmission underwater make it seem that all sounds are coming from directly behind a diver’s head. While this can be confusing at first, after a few dives you will adjust to this aspect of the underwater environment and will hardly notice it.

Underwater Vision

Most scuba masks cut off a diver’s peripheral vision. At first, this can be disconcerting and may make some divers feel slightly claustrophobic. As with most aspects of the scuba diving, new divers will quickly acclimate to their limited field of vision. Imagine that you are driving a new car with some significant blind spots. These blind spots can be annoying the first time you use the vehicle, but after a few trips, you will become aware of exactly where the blind spots are and will learn to turn your head when you need to see into an area which is out of your field of vision. Scuba diving is just the same! If you cannot see you instructor, simply look left, right, up and down and you will find him.

The physics of underwater light transmission have a magnifying effect. Objects appear about 33% closer than they actually are. The implication of this is that your dive buddy, instructor, the floor, the surface, and any other objects seem nearer than they are. Most experienced divers do not even notice the magnification because a diver’s brain quickly learns to adjust to the difference.

A good way to speed the learning process is to reach out and touch objects such as the pool floor, pool wall, or your dive buddy. This will teach you quickly how distant these objects really are.

Never touch corals, fish, or other aquatic life.

Weightlessness and Freedom of Movement:

One of the best parts of scuba diving is the feeling of weightlessness.

Scuba divers can fly up, down, left and right. The weightlessness of scuba diving is one of the most freeing sensations in the world. Divers can move easily in three dimensions. The trick is to relax into the weightless feeling of the water and let the water and your buoyancy compensator (BC) support you.

Don’t fight the water.

At first, a new diver may feel that he needs to move to stay in position — he doesn’t. Try to be as still as possible and enjoy the freedom from gravity. It’s like being an astronaut!

The Density of Water Restricts Movements:

Water is, of course, denser than air. A diver who tries to move quickly will feel resistance to his movements from the water, and may quickly exhaust himself.

Underwater movements, including swimming and arm motions, should be slow and controlled.

You Might Need to Pee:

The human body reacts in unusual ways to the underwater environment.

Being surrounding by water lower than body temperature may lead to a physiological reaction known as cold water immersion diaresis.

The body speeds up the synthesis of urine, leading to the need to urinate underwater. On ocean dives, many divers simply pee in their wetsuits, but if a new diver is learning to dive in a pool, or is using a rental wetsuit, he may need to hold it!

Don’t worry; needing to pee underwater is a completely normal consequence of scuba diving.

Scuba-Diving-EquipmentIt Is Normal to Forget Skills, Hand Signals, and Other Instructions:

The underwater environment exposes new divers to a completely new world. On your first dive, your brain is working hard to adjust to the feeling of weightlessness, the magnification of the water, underwater breathing, and all the other aspects of the environment listed above.

This is a huge amount of information to process, and sometimes instructions which seemed clear on the surface such as the use of hand signals and the steps of underwater skills get pushed to the back of a new diver’s mind. It’s okay!

Be patient with yourself and enjoy the new sensations. It is a new, delightful world down there!

By Natalie Gibb, About.com Guide