Or do you leave your dive plan up to the dive master or instructor? Once upon a time you may have hear something like plan your dive and dive your plan, but with computers today most divers most divers basic dive plan is whatever the dive master says in their briefing and then what their computer tells them during the dive. That is if they have a computer at all.
Let’s review three easy ways to do a dive plan. We will assume that it is our first dive of the day and we are diving on a nice little reef area that is a maximum of 74 feet and we are going to follow the reef along slowly exploring as we work our way to the top of the reef at 40 feet. Being the first dive of the day the dive master calls for a dive plan of no more than 40 minutes.
Looking at the Dive Table it shows us that a dive to 70 feet allows for 40 minutes of bottom time. But since this dive is actually deeper than 70 feet we look at the time limit for 80 feet and see that we only have 30 minutes. Bummer looks like our dive will be shorter that the others or we adjust our dive plan to a max depth of say 65 feet allowing us the full 40 minutes
Or, we get our our handy eRDPml and finding the dive plan mode and following the prompts for multi-level and first dive of the day we see we get 35 minutes for 74 feet. And since we are doing our dive plan, we will plan that depth for say 20 minutes as we will take that long to explore the side and bottom of the reef as we work our way to the top at 40 feet. Again following the prompts on the dive plan tool we see that at 40 feet we now have up to 83 more minutes of bottom time. WOW
But, I will dive plan with my computer. My Computer tells me just what the table does, but since it will take a reading every 20 seconds as I dive my time limit is ever growing as I work my way to the top of the reef my computer tells me that I have 87 minutes of bottom time left after 22 minutes.
See you on the dive boat
Dive tables, like some old classic music cds, still have a place in our hearts and classrooms. And not just from a historical point of view, but from a real world happening now point of view. Most dive shops and instructors teach computers (yes we do), because that is what the over whelming majority of divers are using; especially since they are so easy and in most cases economical for the diver to own. There are even dive operators that will rent you one, free of charge, if you are diving with them for the week and don’t own one. (Owning your own is still the best option as you know how it works.)
But, dive tables are they not going the way of the cassette player? I would argue that is not the case as dive tables have a very real and tangible part of learning to dive and not just because we learned them. Working with students and helping them understand dive tables, while not mastering them, also helps them to understand what the computer is telling them. Dive tables make the no-stop times real in their minds and not some abstract point that they read about in the book or saw on the video. Dive tables and the basic understanding of what they are telling the diver leads to a little better understanding of decompression theory without boring the student to tears. The humble dive table along with its cousins the eRPDml and the dive computer can help us show the student diver that yes our computers allow us more bottom time, but there is no reason to push things to the limits.
I will leave you with this story. A few years ago when dive tables were the primary dive planning tool that we taught, a new diver went to Cozumel for his first ocean dives. When he arrived home he sat down one night and thought it would be interesting to practice his tables based on the dives he had made the week before. The next morning he was waiting for me at the dive shop and looking worried. As he went through the dive week on the dive table with me he stopped right in the middle of it and asked if he should head to the chamber right now because according to his dive tables he should be very sick or even worse. After assuring him he was fine, we reviewed the differences in dive tables and dive computers and how they both function and why dive tables are the most conservative dive planning tool we use.
Did you know that ear injuries are the most common scuba injury? In fact Middle Barotrauma (MEBT) is the leading ear injury among scuba divers with some surveys suggesting that over 50% of all divers have experienced MEBT while fewer than 5% have experienced decompression sickness (DCS). That means that just about every other diver you know has suffered some sort of ear injury while diving. Most cases of MEBT are very mild, heal on their own and in fact are never reported to DAN or any medical agency. It is generally caused by poor equalization techniques or by diving with a cold or allergies.
The second most common ear injury is a ruptured eardrum which again is caused by poor equalization techniques along with descending to fast. What I found interesting in researching for this blog was that most ruptures heal on their own within a few weeks. Can you return to diving after your ear heals? Yes, as long as your doctor clears you and the healing is strong.
Tied for second is our good friend swimmers ear. Now we all know what that is and how to cure it and of course we can go diving again. As soon as that pesky little infection is gone. There are many more serious ear injuries such as Inner Ear Barotrauma and Perilymph Fistual and you can read more on DAN’s webpage.
So how can we prevent the first two types of ear injuires? By equalizing early and often as you probably recall from your open water class. Here are some of the more popular ways to equalize, some you know some might be new to you (Big thanks to DAN.org for this info)
- Voluntary tubal opening: Try yawning or jaw wiggling.
- Valsalva maneuver: Pinch your nostrils, and gently blow through your nose.
- Toynbee maneuver: Pinch your nostrils and swallow.
- Lowry technique: Pinch your nostrils, and gently blow air out of your nose while swallowing.
- Frenzel maneuver: Pinch your nostrils while contracting your throat muscles, and make the sound of the letter K.
- Edmonds technique: Push your jaw forward, and employ the Valsalva maneuver or the Frenzel maneuver.
Mermaid, just the word brings so many images to our minds. From the world of Disney to other attractions at amusement parks or Las Vegas shows. The word mermaid brings to mind lost sailors as they ventured out to sea and of lost treasures.
The first recorded mermaid story is actually from around 1000 BC in which a Goddess accidental killed her mortal lover and being ashamed she jumped in a lake to take the form of a fish, but the waters could not hide her beauty and thus she only grew a fish tale. A very popular legend tells of Alexander the Great’s sister Thessalonike, that after her death she became a mermaid living in the Aegean Sea. She would encounter sailors and ask of them one question, “is King Alexander alive?” Give the correct answer and the sailors would have calm seas for their adventure, but give the wrong answer and the sailors and their ships were doomed.
Mermaid stories are wide spread across history. From Western and Eastern Europe to China to Africa and can even found in Hinduism. In some modern Caribbean cultures there is a mermaid recognized as representing wealth and beauty.
One of my favorite stories is of Columbus in 1493 as he sailed off of the coast of Hispaniola. Columbus reported seeing 3 female like forms which rose high above the sea; but they were not as beautiful as the stories represented them to be. Legend has it that he probably mistook Manatees for humans. Blackbeard the Pirate, in his log book, instructed his crews to stay away from “enchanted waters” for fear of mermaids. Pirates fear mermaids would seduce them out into the waters and steal their treasures.
So, do you believe in a Mermaid? The word comes to us from the old English words of Mer meaning “Sea” and maid meaning “girl”. So yes I do believe in a mermaid, after all they are girls of the sea and we might have just trained a few of them
First how is your weighting? Are you over weighted and constantly using your inflator to maintain proper buoyancy? Maybe you are weighted properly but you are carrying all your weight in one spot and it is dragging you down? Dropping weight or moving it around to become more streamline in the water will help you and your air consumption. By being more streamlined in the water, we glide through the water column in a more efficient manner. If we are over weighted the body wants to have our head up and back arched some which drops our feet putting our body in a less than efficient position and increasing our air consumption as we are working harder than we should be.
Secondly, how is your fining? Are you racing around under water or are you gliding? A nice smooth fining motion with a straight leg is the best way to improve your air consumption. If you are racing around or using a kick that looks like you are riding a bicycle you are exerting more effort than necessary and working harder and increasing your air consumption. Scuba diving is being more like the tortoise than the hare. It isn’t a race, but a nice little stroll under water.
Finally, I know you read in your open water class to take long slow deep breathes. This encourages you to get a nice full breathe and a full exchange of air in the lungs. But what it does is get you thinking about breathing and you actually will increase your air consumption. What we really want you to do is just relax and breathe. If you have been in one of my classes you have heard me ask the question, “How long have you been breathing?” You know how to breathe so let’s relax, breathe and have fun.
Signing up for your Advanced Open Water or a Peak Performance Buoyancy class can help you decrease your air consumption and increase the amount of time you spend under the water.
Nitrox (Enriched Air) just what is it and what benefit does it have for our diving? Nitrox is any blend of air that has over 21% oxygen, hence the tern Enriched Air Nitrox or EAN, with the most common being around 32% oxygen.
The first benefit in diving Nitrox is that by using air that contains less nitrogen we are loading less nitrogen into our bodies therefore at least in theory we are adding a safety margin against decompression illness. With less nitrogen in our scuba cylinders there is even less need to push the limits of the dive tables or our computers. On the regular PADI dive table a dive to 60 feet for 45 minutes leaves us in the pressure group of “S” while on Nitrox of 32% the same dive leaves us in the pressure group of”M”. That is quite a large difference in nitrogen loading.
Which brings us to the next benefit of Nitrox, longer bottom times or shorter surface time. Using our 60 foot dive of before if we look at the regular dive table 60 feet shows a maximum bottom time of 55 minutes and our Nitrox 32% table shows 90 minutes. A huge amount of extra time to spend under water, but not many can make a tank last that long.
So how about shorter surface time? In our 60 foot dive for 45 minutes on the regular PADI table we would be an “S” diver and after a 1 hour surface interval we would have off gassed down to a “G” diver which would allow us only 34 minutes at 60 feet or 54 minutes if we only go to 50 feet. On Nitrox 32% the table is much kinder to our bottom time. If we dive the same 45 minutes and our pressure group is “M” if we want to go right back to 60 feet for 45 minutes our surface time is less than 4 minutes. But since we are safe divers we stay on the surface for 30 minutes which drops us to “H” pressure group and that gives us up to 60 minutes of allowable bottom time.
One last benefit of diving with Nitrox is that you may feel less tired after a day of diving. There is no science that I can point you to, but after 4 or 5 dives a day I know I am less tired
Scuba Myths, we hear a lot of them every day when people come in or call about scuba class so let us take a look at 5 of the most common scuba myths.
1) You need to be an awesome swimmer. Nah, you do need to be able to swim 200 yards in any stroke and it is a non timed swim (300 yards with mask snorkel and fins is an option) and you need to be able to float or tread water for 10 minutes. Basically you should have a comfort in the water since that is where you will be scuba diving
2) Cost of gear and classes is huge. I guess that depends on your definition of huge. How much does that ski pass cost every year? Sure the upfront cost of a good set of mask, snorkel and fins and basic certification can run close to $800, but you will be certified for life and the gear will last you 10 years or more. Compared to skiing, scuba is rather inexpensive.
3) So many scuba myths revolve around aggressive animals and sound like this “Sharks will eat me”. Truth is more people are attacked by dogs that sharks or other aggressive animals. Shark sightings are rare and generally sharks avoid humans as we are close to their size and we are just another apex predator to them
4) To hard to learn and too much time. Another one of the scuba myths that we love. Did you know that it takes a little time at home reading the book and watching the video at your own pace. The actual time in the shop, pool and open water dives is just 2 weekends.
5) My favorite of all scuba myths is “I am too old or out of shape”. Too old? Out of Shape? The goal in scuba is to go slow and see all the little creatures. We don’t have to be an Olympic athlete. We just need to be healthy.
Scuba myths come in all shapes and sizes. What are your favorite scuba myths?
Dive Life, what is it? Close your eyes and imagine your dive life. Are you on an island? Maybe just near the coast. For most I would guess that when you close your eyes you pictured a tropical paradise and you are either leading divers or maybe just hanging around the dive shops. But for us in landlocked locations the dive life means and is something different.
The dive life for me is teaching and one of the best parts about it is that look on the students faces when they first breathe underwater. I am sure you have seen some of their pictures on our face book page and the big smiles that they have. But the dive life is more and to borrow a line from the old Miller High Life commercial; it is “good things for good people”.
Living the dive life is just being active in scuba diving. Taking a class or just getting in the pool and keeping your skills up. Maybe it is attending some social functions wearing your favorite dive shirt and engaging people in stories about your diving adventures and reliving those adventures.
The dive life doesn’t always have to be about scuba diving. It can be anything related to protecting our world and the environment. Recycle or organize a pick up trash day at a local lake or park. After the heavy rains that we have had the last few weeks and the flooding that came with it, I noticed just how many of our drains on the streets of Grand Junction are marked that they empty to the river and just about all of them were covered and blocked by trash. Plastic bags from the stores in every drain that go right to the river and eventually that trash winds up in our oceans. Sometimes living the dive life can just be taking care of the planet that we call home.
Living the dive life is and can be so many different things.
For a few more ideas give me a call and ask about our Project Aware Classes.
Discovery Channel’s hugely popular Shark Week is set to start August 10, but my question is simple. Is shark week good or bad? The ratings are huge and it is must see television for many. And from looking at the line up of 13 fresh and new “shows” I am sure it will be widely watched this year. You can find the line up http://www.discovery.com/tv-shows/shark-week/tv-shows/tv-shows.htm.
There are shows about legendary sharks such as “Monster Hammerhead” and “Lair of Mega Shark” that should be interesting as they are trying to find and prove the existence of these sharks. Much like shows about other creatures of myth and stories and are staples of shark week.
Of course there are the standard features about shark attacks such as “I escaped Jaws”. Where survivors of shark attacks will tell their stories about how and maybe why they were attacked and escaped. As well as the talk show that anchors shark week. Honestly, I think Shark week is better with out this one.
But there are 4 shows that caught my attention and I will be tuning in for them. Of course they are more research style shows but “Zombie Sharks” looks interesting. Apparently there have been a number of Orca attacks on Great Whites and the theory is that the Orcas have been able to create what is called tonic immobility in the sharks. This tonic immobility is a catatonic zombie like state and a professional diver is going to attempt to induce this in a great white.
In “Jaws Strikes back” they will be using some high tech cameras and gear to track the hunting patterns of the great whites. How about “Alien Sharks”? A researcher is trying to find bioluminescent sharks that live in the abyss. And finally, “Spawn of Jaws 2: The Birth”. The birth of a baby great white.
So, is shark week good or bad? I would say it is a mixed bag again this year. Some shows will make the shark lover cringe and some will excite. Some shows will have people saying I am never going to the ocean again. The only thing for sure is that the ratings will be huge
The BCD (Buoyancy Compensator Device) had some very humble beginnings. In fact when recreational scuba was getting started there was no such piece of equipment and the only adjustment for buoyancy was a weight belt to offset the natural buoyancy of the body.
In 1959 the first BCD was starting to show up at dive sites. The horse collar style was the best and most used as it kept the head out of the water and the diver didn’t need to use their hands to hold on to it. There were many experiments on how to inflate this new BCD, oral inflation was the most common and even an auto inflation system was developed. Then someone figured out that they could attach a hose to the tank/regulator and take some air from the diver’s tank to easily and safely adjust the BCD.
In 1971, Scuba Pro introduced and patented the “stabilizer”, which was a BCD with a large air cell that went over the shoulder and around the diver and even the tank. A huge advancement in the BCD, which was copied and modified due to the patent, with the biggest modification being to separate the air cells.
1972 saw the introduction of the AT Pac Wing which was developed by Watergill and is generally considered the first wing style BCD.
The I3 has been a standard in the Aqualung line since 2007, but the I3, which is the lever inflation system used by SeaQuest/Aqualung was first introduced in 1973.
In 1979 the first jacket style BCD was introduced and in 1985 SeaQuest/Aqualung introduced the ADV (advanced design vest)BCD which was an open front with the adjustable shoulder straps. They didn’t patent the design and it is this design that today’s BCD is still using.
• 1959 “horse collar style”
• 1971 Scuba Pro “stabilizer”
• 1972 AT Pac Wing
• 1973 first version of the I3
• 1978 there were 19 models of “horse collar”
• 1979 SeaQuest introduced the jacket style BCD the “Sea Otter” and “Sea Jacket”
• 1980 Octo pockets
• 1985 The ADV jacket introduced and this is still the main style of BCD today
• 1988 the first BCD for Ladies was introduced
• 1990 the first light weight warm water BCD
• 1996 the beginning of weight integrated bcd
As you can see our humble little BCD has grown and definitely been upgraded over the years