Viewing 1 - 9 out of 24 Blogs.

Page:  1 | 2 | 3 | Next >  Last >>

i am not big oncut and paste, but it's better for someone else to write this. :(

Police have recovered the bodies of two Toronto-area divers who went missing in the Welland River on Sunday morning.




Rescue divers search underwater on the Welland River, located two kilometres north of the Niagara River.



Niagara Region police received reports at about 1 a.m. on Friday that a body in a scuba diving suit had been spotted near a water intake system at the Sir Adam Beck hydro generating station above Niagara Falls.
Another body in a scuba suit was discovered after authorities lowered the water flow in the area
The bodies were removed and examined. Police determined they were those of the divers who went missing after being separated from their recreational diving group.
The victims' families have been notified, but police will not be releasing the names of the deceased.
Police said the divers were experienced, but they were faced with strong currents. Two divers were able to escape the treacherous waters during the incident, while another diver had to be rescued.
The particular spot is known in diving circles as a popular location, but police have warned of the dangers in the past.
The river feeds a nearby Ontario Hydro station, which contributes to changing and often ferociously strong currents.

Travelers at risk:
One million Americans embark on diving holidays every year.
Many travelers are exposed to 5 day resort courses with no past experience of diving at home. Many had not anticipated this form of activity and some are not properly cleared medically for diving. Resort course safety records vary from excellent to poor. In general they have a good safety record.

Archeologist, motion picture production, tunnel workers, marine biologists, are other groups involved in diving.

Role of travel medicine specialist:
Scuba is safe for the healthy and well trained .
TM professionals must be able to assess the traveler’s fitness to certify or to permit diving during an upcoming trip or following a minor illness
TM professionals must be able to advise divers about flying safely after diving and evaluate post-diving medical problems.

Diving problems
Problems related to aquatic environment
Hazardous Marine life ( see additional outline on this topic)

Pressure ( increase atmospheric pressure) related problems
Barotrauma
Air Embolism
Decompression Illness
Dysbaric Osteonecrosis
Hearing loss
Compression arthralgia

Environmental exposure problems
Motion Sickness
Near Drowning
Hypothermia
Heat Illness
Sunburn
Allergic reactions ( stings)
Irritant dermatitis
Infectious Diseases
Mechanical trauma
Breathing Gas Toxicity
Panic reactions

3 Gas Laws governing scuba
Boyle’s law : The volume and pressure of a gas are inversely related at a constant temperature. ( increase in atmospheric pressure leads to decrease in volume of gas).
Dalton’s Law The pressure exerted by each gas in a mixture of gases is the same as the pressure the gas would exert if it alone occupied the same volume.
Henry’s Law The amount of gas dissolved in a fluid is proportional to the pressure of the gas at which it is in equilibrium. The higher the pressure, the more gas is dissolved in the tissues.

Barotrauma of descent:
Air pressure within a gas filled space ( middle ear- sinus) normally is in equilibrium with the environment. If this free flow is obstructed ( nasal congestion from a cold) the air will not be able to expand or contract and it will lead to pain and tissue damage known as barotraumas.

Descent trauma or “squeeze” affect the sinuses and middle ears if the divers cannot equilibrate. This dysbaric phenomenon can occur in :

The external ear canal plugged by cerumen -
Middle ear from obstruction of Eustachian tubes – sinus squeeze from sinus drainage obstruction
This type of barotrauma can lead to pain – tympanic membrane rupture – hemorrhage in the middle ear– vertigo- nausea-

Less common are inner ear barotraumas that can lead to injury to the cochlear vestibular apparatus leading to vertigo tinnitus, hearing loss, and possibly disorientation that could lead to a diving accident.

Barosinusitis affects the maxillary and frontal sinuses most often. It leads to pain and bleeding
Miscellaneous types of squeeze include eye or mask squeeze – suit squeeze from trapped air in dry suits-barodontalgia when air is trapped under a faulty dental filling

Treatment :
Abstinence of pressure exposure
Decongestants
Eustachian tube exercises
Anti-inflammatory ( Prednisone)
Antihistamines
Antibiotics ( In case of infections)
Audiogram


Barotrauma of Ascent:
On ascent the trapped gases will expand if they are permitted to escape ( obstruction of air passages) or if the diver does not exhale properly on ascent.

Barotrauma of Ascent leads to reverse squeeze with pain and damage by expanding air in the middle air-sinuses-inner-air.
Gastrointestinal Barotrauma of ascent is caused by expanding intralunial gas in the bowels. This leads to abdominal fullness, colicky abdominal pains, belching, and even vasovagal syncope .

Pulmonary Barotrauma is the most serious form of dysbarism. On ascent the Air in the lung expands continuously Expanding gas will cause the alveoli to rupture producing a spectrum of injuries referred to as the pulmonary overpressurization syndrome or burst lung. Signs and symptoms include pneumomediastinum, subcutaneous emphysema, pneumopericardium, pneumothorax, alveolar hemorrhage. This worse complication is air embolism secondary to air leaking into a ruptured pulmonary vein

Air embolism effects most often the brain but the coronary and visceral circulation may also be affected. Symptoms appear dramatically within 10 minutes of ascent and can lead to acute stroke, paralysis, blindness, confusion, headache, syncope. All patients suspected of air embolism should be placed in an hyperbaric chamber for recompression treatment. Additonal therapy include oxygen, supportive measures.

Nitrogen Narcosis: Nitrogen is a component of compressed air and it has an anesthetic component at elevated atmospheric pressure. Although variable, it usually appears at 70 to 90 feet and at 200 feet it becomes so severe that one can do very little work. It is a reversible condition with ascent and presents similar to alcohol intoxication. It can lead to fatal accident.

Decompression Sickness DCS

During the diving process, nitrogen is released and dissolves into the tissues. Depending on the dept of the dive and it’s duration, the amount of dissolved nitrogen will vary. Upon a too rapid ascent the dissolved nitrogen leaves the tissue but does not have time to re-equilibrate in the blood and therefore forms bubbles. This is similar to opening a can of carbonated drink ( I like beer myself) that has been shaken. These bubbles cause a mechanical and biophysiological effect.
The mechanical effect leads to vascular occlusion ( thrombosis)
The biophysiological effects are on the immune system with release of intrinsic clotting agents, increase in vascular permeability and interstitial edema.
The clinical manifestations are mainly neurological and musculoskeletal.
The most common symptoms are periarticular joint pains- cutaneous rashes, pruritus, lymphatic obstruction (peau d’orange), spinal cord dysfunction, paraplegia, paresthesia, shortness of breath, tachycardia, shock.


Management of DCS
Recompression in an hyperbaric chamber is the primary and essential treatment. Supportive measures such as IV fluids, oxygen, steroids are also indicated.




Medical fitness for Diving:
Prospective divers should be cleared medically before they begin scuba diving.

Disqualifying Medical Conditions for Scuba Diving.
Absolute:
Seizures
Asthma
Emphysema
COPD
Cystic lung disease
Spontaneous pneumothorax
Perforated tympanic membrane
Prosthetic middle ear struts
Ischemic heart disease
Congestive heart disease
CNS disease
Psychosis
Claustrophobia
Pregnancy

Relative
Compromised exercise tolerance
Post myocardial infarction
Hypertension
Insulin dependent diabetes
Orthopedic deformities
Prior thoracostomy
Arthritis
Sciatica
Obesity
Migraine Headache
Allergic Rhinitis

Temporary
URTI
Acute Bronchitis
Acute gastroenteritis
Recent major soft tissue injury
Alcohol intoxication
Decrease Mental alertness

Flying after diving


Flying too soon after diving can lead to port-flight decompression sickness. About 5% of divers have symptoms.
Normal cabin pressure: 4000 to 8000 feet.
These pressures can cause dissolved nitrogen bubbles to come out of solution and form intravascular bubbles. The exact amount of time between the last dive and safe flying still must be established but the following guidelines should be suggested:
1- Minimum surface time of 12 hours between non – decompression dive and flying in commercial jet.
2- For those who have done several days of multiple dives and or dives needing decompression should extend the surface time to 24hours.

Special Travel Insurance

Travelers who will be diving during their trip should be counseled that not all travel health insurance cover diving accidents and that they should confirm adequate coverage. Specialized insurance plans such as the one offered by DAM ( diving alert network) cover a wide range of services aimed at the diver.

Some pictures up from my trip to the smithsonian with 3 buddies.

Enjoy

 

 

 

 

Ok, so this is back in Oman in the 90’s again. Like many pro divers I worked 6 days a week teaching and taking people out to see the wonders of the Arabian Sea. On my day off………I went diving, this time with my buddy Phil and my trusty Nikonos 5. Phil had his own boat a 17ft flat bottom so we only used it when the sea conditions were ok ,Andy worked with Phil and was our guy up top.

This day we decided to go back out to Fahal Island, mentioned in my whale shark blog, to dive a submerged reef located about a half mile from the island. Shallow Reef started at 60ft and went down to about 140ft. To find the reef we used simple transits lining up a part of the island with a house on the mainland (hoping they never demolish said house), depth sounders and GPS were a year or two off for us and of course there were no moorings, this was frontier diving!

We lined up they transits and I threw the anchor in, a sand anchor designed to position us over the shallowest part of the reef, yes I was a ‘Tree Hugger’ back then too J

We seemed to have  a good hold so Phil and I started to gear up just as I glanced over the side of the boat to see a massive dark brown shape with white spots, yes! Another whale shark! We hurried along, knowing that whale sharks like to hang around, we got right in with cameras ready. The plan was to descend to mid water, about 40-60ft down, and see if we could find the whale shark then swim to the reef for the rest of the time. Visibility was great about 100ft, but below us at about 60ft there was a thermocline where the visibility dropped down to about 40ft because of all the plankton. Ideal whale shark conditions J.

Phil and I both had cameras which is not always an ideal pairing, he and I would sometimes get separated doing our own thing but we always managed to stick to our plan and not entirely lose each other. Remind me to tell you about the deep wreck dive we did at night with only one mask! Yes I trusted Phil!

So there we were at 50 ft when I glanced over at Phil, he was waving and yelling, we were about 70 ft apart to maximize the area we were covering. I started to swim over to him when I saw what he was looking at, a huge Green turtle with a massive barnacle growing on it’s head. Phil began haring off after the turtle with his eye in his viewfinder. There was no way I was gonna catch him! I settled for a lazy swim in his direction. So here I was at 50 ft, I could barely see the bottom because of the thermocline but the surface was easy to see. I kept glancing up and around, even though they are so huge, whale sharks can easily creep up on you  unawares J

Phil was almost out of sight when I glanced over my shoulder and saw something huge right at the limit of the visibility. Goody! Here was the whale shark! I settled down to a vertical hover motionless and waited for it to come into view J. Now I consider myself quite knowledgeable about marine life and it did not take me long to realize that this huge shape coming towards me was the wrong colour, grey not brown! The head looked odd and it was moving from side to side. Hmm, remember where I am? 50 ft down, 90ft of water below me and a buddy about 100ft away and this behemoth was dead level with me in the water swimming straight as an arrow toward me!

It got closer and I made out the head, crap, it was a Hammerhead shark and it was a giant! Not to mention, again, that it was coming straight to me. Strangely enough, I was not frightened, in fact I was in awe of this magnificent creature! J It came straight to me and then as I murmered  f%$%$%$%$%g hell into my regulator it made a graceful turn past me. At this point, duh, I remembered that I had a camera and took the picture you see above. The shark’s tail flashed in front of me and I felt the rush of water as it passed my face (don’t worry it was not warm!). The shark moved away from me so slowly that as I followed I could have grabbed it’s tail……….but I did’ntJ. I managed to get off one more shot as it moved out of range, I stopped my pursuit. An easy thing to do with a huge shark. As I glanced over my shoulder I saw Phil swimming as fast as he could towards me, after the dive he told me it was an amazing sight seeing me right next to this huge shark. Pity was he could not get a shot off as he was too far away L. We exchanged a few glances, I was beaming a smile through my reg and mask, and then swam to the nearby reef.

So without making this a 2 part story, we never saw the HammerHead again but when we went down to the reef we hung out near the top. The current was running and there were fish everywhere!. We saw the Turtle with the barnacle again, this time up close. Then just as we were getting ready to leave the whale shark turned up and hung out in the current with us for about 5 mins.

Phil asked me where the boat was, mainly because I have this uncanny sense of direction underwater, and also because he was completely lost. A glance up at the sun and down at the reef told me where the boat was and off we went.

We surfaced safely and as Andy was taking our gear from us he said and I quote “ I don’t know how good your dive was but it’s been amazing up here! I’ve seen Dolphins and when I bang the side of the boat the whaleshark appears!”

Banging away on the side of the boat Andy did indeed ‘call’ the whale shark and we all spent close to an hour with it at the surface, all our film was gone but we hung out for the experience until the sun started to go down and it was time to leave Shallow Reef J

 

So that’s my Hammer Head blog hope you like it!

Note: The remora on the dorsal fin of the hammerhead is close to 3 feet long which allowed us ro estimate the length of the shark at about 17ft, the same size as our boat! The dorsal fin also identifies it as a Great Hammerhead. For those of you that have seen a few Hammerheads you can tell by the small size of the hammer compared to the bulk of the body behind it that this is a huge shark!

Later that week my friend at the marine science centre showed me the jaws of a 14ft Great Hammerhead and I managed to place them over  and down the entire length of my body! J

‘nuff said J

 

Ok everyone, this is not really a blog

not that that's a first or anything!

Anyway, Martythehammer has gone to vegas for a few days and i thought it would be cool if we put up as many hammerhead stories on the blogs before he gets back.

He,s gone about 4 days so get typing, i have about 3 to share

how about it?

So,where was i...

Oh yes, I had just retrieved the marker buoy and reel so the surface boat could actually follow the divers now not the surface current!

My dilema now was to get back to the group, it had taken me at least 10 minutes to find the buoy. I submerged and then began to swim quite hard to catch up, (interesting note, because of the density of water it takes approx  x4 amount of energy to swim twice as fast as normal. On land it takes about x2 amount of energy to walk twice as fast as normal.) I was probably swiming about four times as fast as normal to catch up ( oh oh that translates to about x16 the amount of energy).

Within about 10 minutes I could see the bubbles of the group up ahead, they had reached the North Point of the island. up to this point the underwater terrain slopes gently away from the island down to a depth of about 140ft, however when you reach North Point a rock pinnacle emerges from the water creating a 60ft wall (this is important to know because of what happened next) Being 25ft under the water I had to ascent slightly to go over a ridge to reach the pinnacle and turn a corner at the same time. The group was stationary but it was not because they were waiting for me.

One of the big ones had arrived, another Whale Shark, this one was huge 35ft plus. great! I swam forward and moved in for a closer look. At that point the Whale Shark decided it would do the same thing to me. Not going to get caught out by the same trick twice I immediately started to back of to make sure I was well out of the way of this one. (i like to think I learned something from my previous encounter!) So i kicked back maybe 3 or 4 times and the 'clunk!' I had backed into the pinnacle wall. The Whale Shark kept coming but I had nowhere to go, I did not think it would get me though because only someone as stupid as myself would swim into a wall

I was right, at the last moment in turned aside....relief!

Or so I thought. It is interesting to note that my boss caught everything that happened on video. What happened?

Well, remember the marker buoy and how fast i was swimming, physics caught up with me! The marker buoy had been carried ahead of me by the current and i had neglected to reel in the slack. As the shark passed me by i let out a big sigh of relief, then (and you can actually see this in the video) the trailing line got snagged in the tail! At this point the shark decided it was heading down and I was going with it, I had worked too hard to get the buoy back to lose it now.

Fortunately it came free at about 60ft and all was well

That was until i started to ascend to the group. "thup!" That is the noise your diaphragm makes when there is no air left!

Luckily for me I was diving long enough not to panic in a situation like this, i managed to make my way over to a Dm and grap his octopus and eventually made my way to the surface.

Dive over, what a dive eh?

More to come, I have had a lot of great dives.

Thanks for letting me share

Just uploade one of the other whaleshark shots i took as spoken about on the following blog

Won't be up 2 long coz i don't like to show bad shots

Some of you may have seen a picture i posted very early on my page of a Whale Shark swimming straight towards the camera, some people ( i think) may have even doubted it was my shot. Well here is the story behind that picture.

It was in 1991 that the shot was taken, I was working in The Sultanate of Oman at The Oman Dive Centre just as it opened.

Our plan was to dive a nearby island, Fahal, on the west side for what we called a 'whaleshark expedition'. We had been seeing them regularly there for some time. The profile was to be started at about 6-10m and we would swim from the west to east side as this provided the best opportunity to see the huge animals. When we arrived, in 2 boats, at the site the west side was too rough for safe anchoring and entry. we decided to stop in the northern bay of the island and gear up, one boat would then take the divers in 2 groups to the west side so they could backward roll in. The other would remain in the bay and the first boat would act as a tender/ surface cover for the divers.

I was in the first group and the plan was for my group and i to remain close together on the surface until the other group arrived and we could all descend together. For safety i was carrying a surface marker buoy and reel.

All was going well and I was in the water with the first group waiting for the others. as i got them close together i went over the plan again with them. the last thing i said was 'look out for the whalesharks coz they can pop up anywhere' i literally then just stuck my head into the water (which was v choppy) and yelled 'there!!!!!'

Right under me was about a 15ft whaleshark and off to my left, at the surface was another. at that moment the other boat appeared and I signalled to them to offload their divers while i yelled ' get in ther's whalesharks everywhere!!!'

Two other staff members were in the water with me and the 8 other divers as we stayed at the surface with the whalesharks for 30 mins! I had a small c&c camera with me which i kept in my pocket, just in case, which came in v. handy. My best shot came when one of the whalesharks swam straight towards me and i just kept hitting the shutter hoping to get 'the shot'

As is sometimes the case, objects in the viewfinder appear smaller and further away than they really are! I paused between shots only to see the whale shark was less than 5ft away! It was heading straight for me!, i was not afraid of getting bitten because i know a whalesharks mouth is full of teethlike plates mainly used for crushing large items that end up in their mouths. Rather, i was concerned about getting bumped by  a 15ft shark that weighed who knows how much!

I flipped onto my back and started to fin backwards, still taking pictures, and that is when i got 'the shot'. However, whalesharks swim deceptively fast and i really had to get out of the way, problem was when i moved one way it did the same! Looks like he liked me and wanted to get to know me better

My only option was to vent some air from my bc and exhale for all i was worth. Success! The whaleshark glided harmlessly overtop of me and i even managed to avoid the tail!

My boss then approached me and handed me a video camera and indicated that i should shoot some video of him and the whalesharks, which seemed to enjoy circling back around again and again. i shot about 10 mins of video when the whalesharks decided that they had had enough and moved off.

We marshalled the group together and began descending for the dive, i was to bring up the rear keeping my eyes open for more whalesharks. It was at that point that my boss turned to me with a questioning look on his face, he gave me a signal that looked like he was pulling down on an airhorn or a steam whistle. I had no idea what that meant so i gave him the open arm 'i don't know what you mean' signal. He repeated it and then made a circular motion and looked up. realization suddenly dawned on me, he was asking where was the marker buoy and reel i was supposed to carry

Well when the whaleshark went over my head i let go of the reel

I then received another unknown signal which, strangely enough, i understood. It was 'go and get it!!'

And thats when a whole other experience began

Watch this space, i'll let you know what happened soon

well I have decided that i will write a few blogs to chronicle some of my most memorable dives. They will be posted here over the next few days

Page:  1 | 2 | 3 | Next >  Last >>