Did you just spit into your mask?

Anyone familiar with masks will know that the first thing you do after buying a mask is to rub non-gel toothpaste on the inside and outside of the lenses. The reason is that the manufacturers apply a coating to the lenses to protect them and make them look clean and bright. Somehow, the toothpaste treatment does not always do a good job of getting the protective coatings off.

Before every dive, one should treat your mask in some way to prevent fogging. Commercial defog products like 500 PSI are probably the most popular with divers. The defog products work well and are easy to use and apply. Some divers use baby shampoo as a defog agent. The baby shampoo seems to work just as well. Yet another group of divers use plain old saliva. Some of the veteran divers say that nothing works as well as saliva.

Recently I read an interesting article about a nanotech coating that will permanently prevent fogging on glass surfaces. A scientist at M.I.T. who helped develop the coating, said in the article that the coating will be inexpensive and will never have to be reapplied.

If this technology ever becomes commercially available, you might never see people spitting into their masks again.

Do we really need fin pivots?

The open water adventure went fairly well this weekend. Navigating Phenom (NP) and I had two groups of divers to take through their certification dives. The weather was great, but the visibility was poor. The two groups of divers performed their skills and most did quite fine.

There were the inevitable equipment challenges to deal with. Wetsuits that did not fit, lost masks, underweighted, overweight, regulator free flows and so on. NP and I managed to work through the problems and get everyone squared away. We had to make many trips back to the van to get larger BCD’s, smaller weight belt, more weights and all kinds of odds and ends. Some of the students would wait until just before we were about to enter the water before telling us of some equipment issue. Of course we had to then take off the BCD, weight belt etc, make our way back to the van, retrieve the equipment and help the student.

The worst of the equipment issues were related to adequate weighting. When we give out the weight belts initially, we make an educated guess as to how much weight each person would need. The weighting depends on the build of the person, the thickness of the wetsuit and whether they are wearing hood and gloves. Mostly, we were fairly close with the weight guesses. The problem turned out to be that some students did not know or understand how to do a good buoyancy check. For example, some people told us that they sank too fast, so we removed a little weight. However once we started the first dive, they could not descend and we had to add more weight. I think that some instructors rush through the buoyancy check in the pool and it shows when we get to work with the students in the open water environment.

When it came time to perform the fin pivots, this instructor was not a happy man. Somehow a few of the students thought that a good way to start the fin pivot was to do a good push up off the bottom. The reason was that they forgot to become neutrally buoyant by adding air to their BCD’s. One student refused to lay face down on the platform to start the pivot. The student wanted to do the pivot in mid water. I had a difficult time getting him to start the pivot from the platform floor.

When we had our post-dive briefing, I told the students that the pivots were terrible and we would have to do them correctly the next day or else. Before the next set of dives, I explained in detail what my expectation was of what a correct fin pivot should look like. Fortunately, there was a dramatic improvement in the quality of the fin pivots and everyone did a much better job on the second day.

From my perspective, I do not fully understand why fin pivots are part of the certification process. I think that we can teach and test buoyancy control in many different ways. The teaching process should represent what an open water diver might encounter. That is why we teach mask flood and clears, regulator recovery and so on.

I have never, or seen anyone use a fin pivot in recreational diving. For example, NP is a good videographer and has awesome buoyancy control due to his long periods of pointing his camera at small marine animals. He might come close to doing a fin pivot while photographing, but mostly he keeps off the bottom. In fact, we stress to student divers that they should always keep off the bottom so as not to damage aquatic life. So again, I do not see the place for a fin pivot.

To teach buoyancy control we could concentrate more on hovering skills and some other exercises that more closely mimic what a diver could encounter in the open water environment.

Navigating Phenom's adventure

My diving buddy who I wrote about a few days ago will be referred to as the Navigating Phenom (NP) just to make things easier. A while ago NP and I were talking about his first open water experience. He had the great fortune to be able to do his certification dives on a very scenic island that has abundant marine life. On the first dive, which is really just a tour, he and the instructor were swimming along admiring the bountiful life around them. Suddenly, the instructor became very excited, pointed very excitedly, and started swimming away from NP. At this point NP was very confused, but followed along and suddenly right there in front of them appeared a huge humpback whale.

NP said he was impressed but did not understand at the time why the instructor was so excited. He told me later that he thought that he would be seeing whales on most dives. Of course, he later realized that he was very fortunate to see a whale at all, not to mention that it was his first open water dive! Talk about beginners luck.

Tomorrow, NP and I will be taking two groups of students through their certification dives for open water certification. The weather should be great and perhaps the visibility too. Unfortunately, we are doing our certification dives in a fresh water environment, so the chances of seeing a humpback whale or any significant marine life are out of the question. Perhaps I should take a toy whale along and produce it when NP least expects it!

Taking the first breath

Recently I was thinking of the very first time I was able to experience the joy and thrills of SCUBA. In a way, being able to breathe underwater was almost anti-climactic. I am not sure what I expected, but breathing turned out to be natural and normal, yet very memorable.

One thing I remember from my first pool session was having a dry mouth at the end. Recently a student asked me about why her mouth was so dry after the pool session. The reason I gave was that the air is filtered and moisture reduced before being added to the tanks. So the next question was “what can we do to prevent this?” Unfortunately, I did not have a good answer. I know there are products available on the market to alleviate the dry mouth sensation, but I personally do not know anyone who uses any of these products.

In my case, I do not even notice the dry mouth sensation anymore. I am not sure why that is. Before I dive, I make sure that I am adequately hydrated. By that, I mean I do not drink a huge amount of water, but make sure that have at least the equivalent of two or so glasses of water before the dive. I am sure this is different for everybody, but that seems to work for me. Another personal rule that I have is that I will not have any coffee or carbonated soft drink before a dive. The reason is that I find that coffee, Coke or Pepsi act as a diuretic to me.

One of the instructors that I sometimes teach with has a phrase that he likes to use. He says that there are only two kinds of divers - those who pee in their wetsuits and those who lie about it. However, I do not subscribe that school of thought. I think that if you manage your fluid intake you should be able to manage the bladder situation. I know that everyone is different, so I guess if you have to go, then you have to go. Personally, I find the thought of diving in a “suit of pee” not attractive at all.

Experienced divers probably do not think too much about the act of breathing from the regulator. However, the memory of my first nervous and excited breaths from the regulator will always be with me.


Update: 09/07/05: Article by a doc on the effects of pressure on bloodflow and the bladder.

Technology and diving

Getting lost underwater can be a very scary experience. Some people, like my diving buddy is just a natural at navigation. I always tease him about his heritage because I tell him that being able to navigate is just in his blood. He has an uncanny ability to find his way back to the dive boat every time.

On the other hand, I do not have the navigation gene. For me, it takes a lot of effort and concentration to find my way around. Fortunately, I am quite observant so I often dive using natural navigation (for example, by following natural markers, or using the sun when possible). In lakes, sometimes I would follow a weed line or a contour.

Using a compass did not come easily for me. I had to really work on my compass navigation skill. As the old say goes – practice makes perfect. The more you use the compass, the better you get at it. On dives I sometimes force myself to follow a compass heading, even if I know the area perfectly well and don’t need the compass. It is important to keep compass skills fresh.

Recently, I was talking to fellow instructor about using GPS to mark some of our regular diving spots. As most people know, GPS does not currently have a strong enough signal to penetrate into water (beyond say a few inches). So what my fellow instructor was going to do was attach a GPS unit to the dive flag and circle around the spots of interest. Later the instructor would be able to get a fairly good GPS location by using the circles on the GPS screen.

There is no doubt that technology is making diving safer and more enjoyable. I guess the day will come when divers will have some kind of unit that will work like GPS systems in cars. However as in most things, it pays to be able to navigate using the compass and natural navigation. The same can be said for tables and dive computers. A good diver will always be able to plan a dive without a computer. The computer should be used as an extra safety factor, but a responsible diver, should be able to plan the dive by using tables. It is vital to understand the relationship between depth, time and nitrogen loading.

By far, the best piece of technology that a diver has is his or her brain.

Night Dive - fear or fascination

Diving at night seems to be one of those things that people either love or hate. I know of divers who absolutely love diving at night and I know of other divers who would have a serious panic attack if they had to go into the water after dark.

A good way to get students accustomed to being in the water at night is to schedule the night dive for when there is a full moon and to start the dive at dusk. The students enter the water and can see fairly well with the available light. Once submerged, the divers become comfortable with the familiar feelings of being underwater. Eventually it becomes dark and most students do not even realize the gradual change from dusk to darkness. Often students are surprised by how well they can see underwater after dark.

A comprehensive dive briefing and orientation helps to calm the more nervous students. Post dive debriefs also helps students process the night dive and enables you to clear up any uncertainties.      

Cold water

I heard an interesting interview on a local radio station. The host of the radio show interviewed one of the survivors of a plane crash in the Bering Sea in 1993. The story has many interesting facets to it. Below is a direct quote from the website http://www.therescuestory.com/ Additionally this newspaper article gives a very good account of the rescue.

"In August 1993 on an ordinary day, a small plane ran out of fuel 45 minutes into a 75 minute flight and had to make a crash landing. The fact that everyone on board survived may seem like a small miracle or maybe no miracle at all, just pilot skill. But consider this: the plane ditched in the Bering Sea, off of Alaska, 2 1/2 miles from the nearest land and 22 miles from their destination. The plane did not carry a life raft or life vests; the water temperature was in the 30's."

The survivors managed to survive in near arctic waters for almost 70 minutes. Typically the expected survival time in such frigid water (-1 degree Celsius) is probably around 10 to 15 minutes

Having experienced very cold water myself, I can only imagine the agony these people must have endured. At least I had thermal underwear, full drysuit, hood and gloves on when I did my cold water diving. The water, in my case was bracing, yet bearable (except for the brief "ice cream headache"). However, without exposure protection, enduring ice cold water can be very painful and possibly fatal. As many people know, water conducts heat away from the body four times faster than air does, since water is a much better conductor than air is.

Hypothermia is an insidious enemy. Hypothermia occurs when the core body temperature is less than 35 degrees Celsius. Loss of consciousness or decreased consciousness occurs when the core body temperature drops to 30 to 32 degrees Celsius. Heart failure is the usual cause of death when the core body temperature drops below 30 degrees Celsius. The key to survival is therefore to try to preserve body heat. See this webpage for more information on how to improve your chances of surviving hypothermia in water.        

What a freeloader.

The last few posts have been a little on the serious and technical side, so I thought a change a pace might be a good idea.

Last year I met a very friendly and happy fellow diver who has one of the keenest senses of humor that I have encountered. However, he is a confirmed bachelor and is perhaps on the side of the fence that feels that marriage and relationships are much better left well alone (something about a messy divorce and being taken for a ride etc).

One day there were three of us diving together in a group and toward the end of the dive, our friend decided that he needed to get back to the boat. So we directed toward where the boat was and continued on with dive. In case you were wondering, the boat was close and our friend is a very experienced diver.

After the dive we changed out of gear and proceeded up to the deck to see why our friend had to abort the dive so early. It turned out that he needed to get back to the boat because of some biological issue (don't ask).

But this was not the real cause for great laughter and much teasing that day. It turned out that as soon as our friend left us, a Remora (slender sucker fish), wanted to attach itself to our friend's leg. The problem was that nothing he did, could persuade the troublesome freeloader from leaving our friend alone. He tried to frighten it away with a blast of air from his regulator, tried to swat at it and even tried to stab it with his diving knife. According to our friend, the fish was entirely convinced that its life depended on attaching itself to his leg. Apparently the Remora followed him all the way up to the boat and I am sure if it could it would have followed him onto the boat too.

Of course this juicy piece of information became widely known on the boat and thereafter the Remoras were known as his girlfriends. So it seems that even the female fish of this world wanted to take our friend for a ride!

For more information on the Remora see http://www.amonline.net.au/fishes/fishfacts/fish/enaucrates.htm

http://www.gma.org/fogm/Remora_remora.htm

Deep safety stops

Last year while diving with some divers from all over the country, we discussed various safety stop strategies. Of course we were very strict in keeping to our three minute safety stops at 15 feet.

Personally, I do not view the safety stop as a waste of time. It is a time of reflection on the dive, and also a time when I can practice buoyancy control and various other skills. I need to keep sharp on my skills and use this time as extra practice time (for example mask clears etc).

One technique we discussed and which I have became very interested in, is making additional deep safety stops. There are a number of ways to do the deep safety stops. One method is to make one minute safety stops at 50% of the depth, then 25% and finally three minutes at 15 feet. For example if your dive to 100 feet, then you will do a safety stop at 50 feet, 25 feet, and the usual 15 feet. Some people even will do a further short safety stop at 7.5 feet.

Another method would be to make a deep safety stop at 50% depth for 1 minute and then a 2 minute stop at 15 feet. However, I think that a 2 minute safety stop at 15 feet is too short, but there is a research project underway to test this theory (see website mentioned below).

There is an interesting article about deep safety stops at the DAN website The authors delve into a fair amount of history and theory but it is worth reading.

Interestingly, the 60 feet per minute ascent rate seems to be on the high side. It would seem that the more prudent ascent rate would be less than 30 feet a minute. From the DAN article, it seems that 60 feet a minute was decided without too much scientific evidence and research.

In case anyone might misunderstand - please ascend NO FASTER than 60 feet per minute (the slower the better) and ALWAYS make a 3 minute safety stop at 15 feet (air supply permitted of course).

What is the most important rule in SCUBA?

What is the most important rule in SCUBA? The answer to this question is drilled into our students, "Never hold your breath". However, I would like to add a second and third rule. The second rule is dive within your limits and the third rule (perhaps a little facetiously) is always read the fine print.

Recently an article appeared on Divernet.com that a British diver is faced with a huge bill of £40,000 for medical treatment due to decompression illness (see http://www.divernet.com/news/stories/130805bill.shtml). It appears that he violated the conditions of the insurance by diving deeper than the30m (90feet) limit of the policy. According to the article, his maximum depth was 49.5m (approximately 150feet).

Please don't misunderstand my comments below as directed toward the unfortunate gentleman mentioned in the article. I merely want to draw some general conclusions from the article and in no way am I saying anything about the diver, his skill or the treatment he received.

There are two immediate conclusions to draw from the article. The first is that one should know what the conditions of the insurance policy are before diving. Some insurance policies are very strict about depth limits etc. When it comes to diver insurance, cheaper is not the way to go.

The second is a general observation about safe diving practices. Recreational divers are certified to dive to a depth of 40m (130 feet). However, most training organizations recommend that dives are limited to 100 feet or shallower. The problem with deep diving and physiology is that each person is affected differently. Two divers of similar age and experience can do exactly identical dives and one could be affected by decompression illness and the other one not.

There are many factors that affect and influence one's risk factors. In this specific case dehydration could have played a major role. The key point though is that one should dive well within one's training and ability. Discretion is always the better part of valor when it comes to recreational diving. The dive insurance that most divers use that I am familiar with is Divers Alert Network.

The insurance that DAN offers is sold in three tiers. At the most basic level the insurance covers dives up to 130 feet.(http://www.diversalertnetwork.com/insurance/plans.asp)  The more expensive options cover dives to any depth. From anecdotal evidence it is clear that DAN is very supportive of divers. Sarah M let me know via a comment that DAN insurance is available in Europe – the head office is in Italy.

One can never be totally sure that you will not be "hit" by decompression illness. Therefore one should always dive to safe and established guidelines and remember rule number 3: always read the fine print of the insurance policies!        

But aren't there sharks in the sea?

One of the most frequent questions I get while teaching the entry level classes is about sharks. We do spend a little time talking about what to do if you encounter a marine animal that could pose a danger to you. The thing to remember of course is not to provoke the animal or corner it. Mostly, the larger marine animals are curious about divers and do not view divers as a source of food.

However, sharks evoke a great deal of emotion from divers. Even experienced divers become very nervous at the sight of a great white. These majestic animals can grow to huge lengths and have jaws and teeth to match their awesome reputation. Recently I read a very interesting post about three divers who encountered a huge great white off the coast of South Africa. The story is written from the perspective of the dive master. The divers survived, but I am sure they had an experience that they will never forget.

From my perspective, I have grown fairly interested in sharks in the past year or so. At first I would have nothing to do with sharks and would go to great lengths to avoid them. I guess the problem was that I was influenced (like just about everyone else) by movies like Jaws and other misinformation in the popular media.

Sharks are not the mindless killers that they are sometimes portrayed to be. Sharks like every other animal have instincts that guide them and conform to behavior that is common to their specific species. For example there are really only approximately 39 out of 368 recognized species that are known to have attacked humans, but most attacks are thought to be accidents (probably cases of mistaken identity). There are many factors that contribute to shark attacks, but if you are faced with fending off an overly curious or aggressive shark, you could take a look at the information at this site (link included for information purposes only).

The great white (carcharodon carcharias), bull shark (carcharhinus leucas) and tiger shark (galeocerdo cuvier) are thought to be the most dangerous of the shark family. Each of these sharks is called by different names in different parts of the world. Of these, the great white sharks are the most fearsome and predatory of the group.

From my personal experience, I can honestly say that my irrational fear for sharks has changed to respect and admiration for these perfect "hunting machines". Having been in the water with nurse and many reef sharks, my conclusion is that these animals are graceful, beautiful and nimble. They are something to behold in their natural environment.

I would not like to encounter a huge great white without the security of a cage, and will not participate in chumming. Chumming to my mind sets a dangerous stage where the sharks are artificially lured to where the humans are with fish blood, fish parts and so on. The problem is that eventually, the sharks are conditioned to associate humans with the regular feeding activities. This is not a natural part of the shark's life and the concern is that eventually sharks might associate humans with food. I am not a shark expert by any means, and defer to my friends who are marine biology experts, but the constant feeding and chumming cannot have a good outcome.

Times are changing

In a recent training bulletin from PADI a quotation from DAN (Divers Alert Network) appeared with regard to nasal decongestant use with diving.

Nasal decongestants such as oxymetazoline (Afrin and generic) can temporarily reduce the swelling of nasal mucosa and may facilitate middle ear and sinus equalization during diving. Some degree of '‘rebound'’ (increased mucosal swelling) can occur after the effects of the drug wear off. However, the effects of oxymetazoline usually last for up to 12 hours, thus it is unlikely that the effects will wear off during a dive unless the previous dose was administered several hours before the dive start. Some nasal decongestants (e.g. phenylephrine, Neosynephrine) have a shorter duration of action than oxymetazoline, and are associated with greater rebound. Prolonged use of any nasal decongestant can be associated with severe rebound nasal swelling; prolonged use is discouraged beyond what is necessary to provide short term relief of symptoms or to promote middle ear or sinus pressure equilibration. For oxymetazoline nasal spray, once daily use for up to 5 days is unlikely to be associated with significant rebound effect after it is stopped.

It is interesting to follow the developments with regard to nasal decongestant use and diving. There seems to be a change in the way that decongestants are viewed from a diving perspective. The use of decongestants has been a source of many debates in the diving community. The one camp (mostly dive training organizations etc.) laid down strict guidelines that decongestants should not be used before diving. The other group felt that there was a place for decongestant use, especially long acting ones.

The main issue appears to be the problem of reverse squeezes. In a reverse squeeze situation, the effect of the decongestant wears off during the dive and upon ascent, the pressure in the inner cannot equalize to the ambient pressure of the water around the diver (in the ear canal - outer ear). This is a very painful situation that can lead to serious medical problems. The real problem is that a diver could be faced with making a decision of either rupturing an ear drum or running out of air. Not a good choice.

Disclaimer: please consult your physician about taking any medication before diving - especially decongestants. The safe and prudent thing to do is of course to consult a physician. If you can find a physician who is a diver or is experienced with diving medicine all the better.

What was that gesture you made?

One evening, I was eating at one of the regular dining establishments that I frequent. I was reading the latest edition of the Undersea Journal and eating a hearty meal, totally engrossed in my own little world. Just as took a mouthful of food, I heard a voice asking if everything ok (with my meal), but I didn't really think about it too much and just proceeded to give the server the universal "OK" hand gesture. I suppose I am such a creature of habit that a simple nod or thumbs-up didn't seem obvious at the time.

This event had me thinking about how my life has changed (in many subtle ways) since I have been diving. Often I find myself using a "thumbs-up" gesture to indicate "up" and "thumbs-down" for "down". I found myself using the "thumbs-up" gesture a few weeks ago when I was trying to explain to my non-diving friends how the price of something had just shot up recently.

None of this is really a big deal in the greater scheme of things I know. However it is interesting to me how even simple hand gestures in my regular conversations have been influenced by diving. I guess you can spot a diver anywhere by asking him or her which way up is!

Tables, tables and more tables

One of the more challenging parts of teaching the entry level classes is to convey the theory and practice of the recreational dive planner (RDP). The RDP that we use consists of three tables. Each table has its own purpose and reason for being. I suppose to the students learning and applying the RDP to diving profile planning is much like going to the dentist - painful, but necessary.

For most of the classes that I teach we manage to get through the RDP without too much trouble. However, recently I had one of those classes that seem to be a little more challenging. It seemed that I had more than my fair share of RDP challenged students in one class (not that there is much mathematics involved, just logic and being careful to apply the correct method).

I decided to teach the RDP at the most elementary level that I have ever presented the material. I assumed nothing and explained every obscure and obvious element. I had one student that was absolutely brilliant. She managed to complete the quizzes and exam in a record time (scoring mostly 100% every time). The snail's pace must have been torture to her.

Eventually after much explanations, discussions and examples it was time for the quiz. I asked the students to start the quiz with a heavy heart. I was sure that my words had not had much effect and that I would have to schedule another "RDP evening". Eventually I received the quizzes back and surprisingly ALL the students scored very well on the RDP portions.

Perhaps a valuable lesson learned - never assume that the students will not eventually "get it". However, the next time I teach the RDP, I will teach the class in the same way as I did with this class. Assume nothing and explain every obscure and obvious detail. Unfortunately the quicker students will be bored silly, but knowing how to use the RDP and being comfortable with using it is vital to safe diving.

Are you ready?

I was reading through a blog from a great writer in South Africa and found the following gripping post.

http://africandust.blogspot.com/2005/01/absent-from-body.html

I link directly to the post, since I cannot even begin to do justice to the way Clare wrote so eloquently. The story gripped my heart and I could feel the pangs of sorrow and pain that she wrote about.

From my perspective the story symbolized many things. The most important is that we need to be ready to transition to eternity at any moment since being absent from the body is to be in the presence of the Lord. The second is the selfless way that Dave Shaw dove 270 meters (approx. 810 feet) to recover the body of a fellow diver.

Another link to a news article that describes the rescue attempt.

To pivot or not to pivot

One of my greatest challenges is trying to get students to do a fin pivot correctly. Surprisingly, doing the fin pivot is easy, but my challenge is explaining the technique to the students in a way that they can remember and apply.

For those who do not know what a fin pivot is let me explain briefly. The diver lays face down on the bottom of the pool in the deep end of the pool and by controlling their buoyancy, the diver should be able to pivot on the fins tips by moving the upper body up and down around 18 to 24 inches.

The problem seems to be that some people think that the way to start the pivot is by doing a "pushup" off the bottom. Alternatively, the students tend to over-inflate the BCD and shoot to the surface.

Occasionally students will just be terrific at the skill and that makes this instructor a very happy man.

Not all classes are created equal.

Sometimes it seems to me that classes take on a personality all of their own. With some classes everything flows smoothly and we don't have even the smallest hint of a problem. However, the class I taught recently was different. I knew from the start it would be a "different" class when at least half the students were still trying to buy masks, fins and snorkels minutes before the class was scheduled to start. Unfortunately, the poor fellow working on the retail side was swamped and the class started late.

It seemed like my instructions were bouncing off the walls. I had to repeat the same instructions three or four times before it seemed that the students understood. Even with the many repetitions, some people just did not pay attention, and when we submerged to perform some skill, they just did not know what to do. These same people were bantering, playing with their gear and generally goofing off while I was trying to demonstrate the skills on the surface. As much as I tried to get their attention and reign in the craziness, it seemed that my best efforts were not having much success.

Don't misunderstand my comments though. I have a great deal of fun teaching these classes and enjoy working with the students. I am just amazed how the personality of a class can change from the one to the next.

Are you OK?

A few years ago, I had a student (lets call him Ed) who was from a foreign country. It does not really matter which, but he was not very fluent in English. I mention this only because of what occurred later. At the beginning of the class, like every other class I teach, we reviewed communications procedures and of course I always mention that the "OK" sign is both a question and an answer. Up to this point in my teaching experience, I thought that this statement was fairly self evident. "I ask you if you are ok and you respond ok". Simple stuff right?

The class was progressing along at a fairly good pace, but Ed was having some difficulty understanding my instructions. Sometimes he responded to the "OK?" and sometimes not. So trying to be the good instructor I remained patient and explained the importance of communication again. Unfortunately, Ed was having all kinds of problems, and at this point I was wondering if he really should be in the pool at all. He was trouble clearing his mask and it seemed like it was a poor fit. I advised him to try to get a replacement for the next class.

Eventually we submerged and moved down to the deep end of the pool to continue with the skills at the deep end. When we eventually all arrived at the bottom, I started going around the class with the "OK?" signal. All the other students indicated that they were "OK", but I was getting no response from Ed. So I tried three or four more times to get an OK from him. Nothing doing. At this point I was getting more than a little frustrated. I was thinking - how selfish of him - holding up the class like this. He is looking straight at me and is not responding! Is it that he did not understand what I meant with the "OK?". Was it due to him being from another country or was he just not cut out to be a diver?

In frustration I swam over to him and right in front of him I again gave him "OK?" sign. Nothing again. I was getting really steamed.

Then I took a closer look at this mask. His mask was completely flooded and he just sat there, quite content with a mask full of water. Obviously he could not see my many requests for "OK"! I felt really dumb.

Fortunately, with some additional work, Ed managed to complete all the required skills and later I heard from his open water instructor that he managed quite adequately with the open water dives.