Underweighting can be just as dangerous as overweighting.

scuba diver in lotus position

Equipment and the Environment Will Both Affect Your Buoyancy

Wetsuits, tanks, and even accessories and tools will affect your buoyancy. Whenever you change one of these items, it is necessary to complete a buoyancy check to determine the effect of the new item on your buoyancy. The salinity of the water will also affect a divers buoyancy. The obvious example is buoyancy in fresh water vs salt water, but keep in mind that the salinity of the ocean may also vary in different regions of the world, and you may need slightly more or less weight depending upon your dive location.

Conducting a weight test before a dive can make the difference between a miserable dive and an enjoyable one.

 

Conduct a Buoyancy Check Before DivingScuba 2

Test your buoyancy in a new location or whenever diving with a new piece of gear. Most of the time, diver’s have a limited number of dives on vacation, and it is worth the effort to make every dive comfortable and safe.

In fact, most dive operators will be thrilled if you ask to wade into the ocean or hop of the pier before your first dive to double check your weighting.

 

The general rule of thumb for proper weighting is that with all of his gear in place, with a nearly empty tank, a diver who completely empties his BCD and holds a normal breath should float at eye level. When he exhales he should sink.

 

Remember!! As the tank empties, it will become positively buoyant.

If you can empty your BCD, hold a normal breath, and float at eye level at the beginning of the dive, you will not have enough weight to comfortably maintain neutral buoyancy at the end of the dive.

The problem here is that most dive shops are not in the practice of providing nearly empty tanks for buoyancy tests. There are two solutions to this:

 

  1. Conduct the buoyancy test with a full tank as outlined above, and then add the appropriate amount of weight to offset the buoyancy swing of your tank as it empties.
  2. Conduct the buoyancy test as outlined above with a full tank, but instead of checking that you float at eye level, check to see that you sink slowly while holding a normal breath.

 

Double Check Your Buoyancy at the End of a Dive

Once you have successfully completed a dive with enough weight to keep you comfortably below water the entire time, it is a good idea to double check your weighting at the end of the dive.

To do this, purge your regulator gently until you are down to about 500 psi or 30 bar. Then, on the surface, conduct a buoyancy check before exiting the water. Do you float at eye level and sink when you exhale?Scuba 3

Do you have to swim to get down? Float like a balloon on the surface? Add a little weight on your next dive.

Do you still sink while holding your breath? Remove a few pounds and try again on the next dive.

 

Adding a Small Amount of Air to Your BCD During Descent Is Good

Many divers seem pleased that they can descend and arrive at the planned depth without adding air to the BCD.

Again, this is not a desirable situation. Because most tanks become more positively buoyant throughout a dive, divers who do not need to add air to their BCDs during descent to establish neutral buoyancy are likely to be underweighted.

 

I Don’t Need to Add Air During Descent. I Am Fine at the End of the Dive!

These are the people who have exceptionally low air consumption rates, and surface with at least half of their air remaining. Yes, they can be perfectly neutral during their safety stops, and they don’t go flying to the surface like awkward buoys at the end of the dive. Their tanks have not become positively buoyant because they haven’t breathed enough gas to cause a buoyancy swing.

 

The problem with this habit is that it does not prepare divers for an emergency situation, when they are low on gas because they over-breathed a tank due to a stressful situation, surface with less gas than normal due to an unforeseen occurrence, or are forced to share air with another diver.

In these situations, such a diver will have trouble staying down, and of course, these are the situations when having enough weight can make a big difference between an annoying situation and an uncontrolled ascent to the surface.

Plan for the worst case scenario: a low tank and increased breathing rates due to stress.

 

Diving with less weight does not make you a better diver.

Diving with the correct amount of weight does.

Slight overweighting is correctable: just add a little air to the BCD.

To be safe on dives, proper weighting is key.

Take the time to get your weighting right and you can avoid many potentially dangerous situations and dive more comfortably.

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.

 

 

 

Basic Shark Facts For Scuba Divers – By Monique Mancilla and Daniel Ponce-Taylor

Bull-sharks-with-scuba-divers

For many people, the word “shark” conjures the image of a dangerous animal, a killing machine out to attack humans.
This could not be further from the truth. In fact, a person is more likely to be struck and killed by lightening than attacked by a shark.
Worldwide, sharks only kill 4 – 5 people a year.
Instead of fearing sharks, divers should realize that sharks are fascinating animals that play an essential role in maintaining balance within marine ecosystems.
Here are some interesting facts that divers should know about sharks.

Are Sharks Fish?:
Although sharks, skates, and rays do not have scales, they are still classified as fish.
These creatures are all members the cartilaginous fish group; instead of bones, their bodies are supported by cartilage (like a person’s nose).
Cartilage is more flexible than bone, giving shark fins an almost rubbery appearance.
As migratory fish, sharks spend most of their time in open water.
With more than 400 types of sharks on the planet, shark species demonstrate great diversity in size, appearance, habitat, and behavior.

Sharks Frequently Lose Teeth:
One of a shark’s most recognized characteristics is a mouth of sharp, scary teeth.
As an apex predator (meaning that sharks are at the top of the food chain),
a shark’s teeth need to meet the challenge of eating the wide variety of animals below it on the food chain.
Without teeth, a shark would be unable to survive, so sharks have an interesting way of dealing with broken or lost teeth.
Shark teeth are embedded in the animal’s gums and can come out of a shark’s mouth relatively easily.
Rows of replacement teeth grow along the jaw and move forward when a tooth needs to be replaced.

Do Sharks Really Eat Humans?:
With a keen sense of smell, sharks can detect blood in the water in quantities as little as one part per million.
Sharks have very specific food preferences and humans are not at the top of their menu.
A shark will either vomit out an unfavorable food item or its stomach will turn inside out to eject it.
Of over 400 shark species, great white, tiger and bull sharks are responsible for the majority of (the very few) attacks on humans.

Sharks Have a Sixth Sense:
Sharks have a network of jelly-filled pores which are used to detect electromagnetic fields produced by other animals.
This can be though of as a sixth, “electromagnetic sense”.
A shark’s electromagnetic sensing cells are known as the ampullae of Lorenzini, and can help a shark to find its next meal.
Sharks are the most electrically sensitive animals on the planet, and are even capable of finding prey hidden in sand by honing in on the prey’s electric field.
Sharks can also sense the electric fields generated by ocean currents, aiding them in navigating the ocean.

Fun Sharks Facts and Trivia:

  • A shark on land would be crushed by its own weight. Sharks lack a ribcage to maintain body structure.
  • Most sharks have eight fins. Despite this, they cannot back up. Their fins do not allow them to move tail-first, which means they eventually drift over objects directly in front of them.
  • Despite its numerous teeth, a shark’s digestion is very slow.
  • Many shark species must maintain constant motion to keep water flowing over their gills. If they stop swimming, they do not receive sufficient amounts of oxygen to survive.

Reduce the Risk of a Shark Attack While Diving:
If you are worried that you are going to be attacked by a shark, here are a few tips to decrease the already tiny chance of being attacked by a shark.

  • Avoid diving in waters with poor visibility as it increases the chance of a shark mistaking you for something it normally eats.
  • Avoid diving at dawn and dusk, as this is when many species of sharks are most active.
  • If a shark is spotted, find your dive buddy and stay together. Sharks are more likely to attack solitary individuals than members of a group. Seals use the same defensive strategy with white sharks in South Africa.
  • If you are lucky enough to see a shark while diving, stay calm and keep an eye on it.
  • If you do not feel safe with the shark then slowly swim to the dive boat or shore to exit the water

The Take-Home Message About Diving With Sharks:
They are a beautiful but threatened group of species.
Instead of fearing sharks, divers should cherish swimming in presence of these amazing and increasingly rare animals.
Each year, up to 100 million sharks are killed for their fins, jaws, teeth, meat, or by accident .
On average, for every human killed by sharks up to 20 million sharks are killed by people.
Divers, and people in general, should stop fearing sharks and start protecting them.

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.

Scuba Wetsuit Care 101: Removing Odours & Extending Suit Life – By Christine

75-anniv-wetsuit-7

If you want your wetsuit to last as long as possible, a bit of proper wetsuit care is all you need. The difference between a wetsuit with a 1 year life and 6 year life depends, to a certain extent, on how often you are using it. But to a larger extent, how well you take care of your wetsuit is going to either quicken or slow its deterioration. Below are 13 care tips for extending wetsuit life.

1. Neoprene and Hot Water Are Not Friends

Neoprene loses some of the flexibility when soaked in hot water. So hop in a cold shower with your wetsuit on or only soak it in lukewarm water.

2. Sun & UV Rays Deteriorate Neoprene

Sun and UV rays both cause your neoprene wetsuit to age more quickly. So if you need your scuba suit to dry, don’t try to hasten the process by placing it in the sun. In the long run, the neoprene will become hard and lose flexibility.

3. Don’t Put Your Wetsuit in a Hot Trunk

If your car has been sitting in a parking lot on a hot day, then putting your wet suit into the trunk is not a great idea. This will essentially “cook” your gear, increasing smells and breeding bacteria.

4. Turn Your Wetsuit Inside Out to Dry

To dry your wetsuit, its best to first turn it inside out before hanging it up. By turning the suit inside out, flexibility will be maintained on the outer side. This means that even if the wetsuit it not 100% dry to next time you put it on, you’ll for sure be crawling into a drier side.

5. Carefully Store

Carefully store your dry wet suit on a flat surface or hang on a wide coat hanger in your closet.

6. Quickly Clean & Dry Your Suit

After a dive, don’t let your wet wetsuit sit in your dive bag, all stinky, messy and sandy. Clean the suit quickly and dry it completely before storing away. This type of regular wetsuit care will be sure to increase its lifespan.

7. Avoid “Messy Dressing”

If you’re doing a beach or shore dive, keep your wetsuit up and aware from the mud/ sand. Its not so comfortable to pull on a sandy wetsuit! Also, when you take off your wetsuit, stand on pavement, a rock, your changing bag, grass or anything besides the middle of the sandy beach.

8. Wetsuits Don’t Belong in the Washer

Neoprene wetsuits must be handled with care and can’t be put through the washer and dryer. You have to hand wash and air dry.

9. Can I Iron my Wetsuit? …. No!

It’s a no-brainer that you should not iron your wetsuit. Just look at the rubber areas around the zippers and knees. Also, if you were to iron the neoprene, that amount of excessive heat would make the suit very stiff.

10. Bleach is Off-Limits

Strong washing agents, such as bleach, are way too harsh for your neoprene wetsuit (not to mention the discoloration that will occur). There are some mild cleansing agents, such as “Sink the Stink” and “Trident Wetsuit Cleaner” that you can purchase from your local dive shop, but regular dish detergent will work just as well (read on to find out how to get rid of wetsuit smells on your own).

11. Why Does My Wetsuit Stink?

Your wetsuit can stink if it was left, wet, in a bag for a while and wasn’t rinsed. The smell comes from bacteria that begin to feed on the normal sweat and body oils and odours clinging to the wetsuit after we use it. Also, if you urinate in your wetsuit, the pee can leave an odour behind.

12. How to Get Ride of Wetsuit Smells & Odours

As I mentioned, there are special cleaning soaps and solutions for getting rid of wetsuit odours, but I personally, find that there is an easy, more economical way to erase suit smells.

Here is my home made recipe for washing smelly wetsuits:

1st: Fill the tub up ¼ of the way with fresh, warm (not hot) water.
2nd: Add a couple tablespoons of dish washing detergent, just enough to get a dilute bubbly water bath for soaking.
Note: Some people will use laundry detergent, but I think even that is too harsh for neoprene (and tougher to rinse off). The only laundry detergent to consider using is Woolite.
3rd: Wash your wetsuit in the tub of soap and the detergent will break down the body oils and odours. In addition, it will help wash away the bacteria that caused the smell in the first place .
4th: Rinse your wetsuit in fresh water in order to get all the detergent off. Then hang your wetsuit up to dry in the fresh air (away from direct sunlight).
5th: Every few weeks, repeat this process to keep your wetsuit completely odour-free!

Christine Beggs is the founder of Project Blue Hope, a site dedicated to spreading her wish for a “Future of Blue.” Currently pursuing her Master’s degree in Marine Conservation, Christine is passionate about ocean health and the preservation of coral reefs. Join the discussion about marine issues @ProjectBlueHope and www.ProjectBlueHope.com to help spread the word for more balanced oceans.