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Post by vance on Mar 17, 2018 15:39:18 GMT -8
Don't worry about it DRW, you'll be a'ight. We won't bash you. Snorkles is snorkles.
Have you ever tried the garden hose snorkle? Many of us (as kids) thought that if you got got a garden hose and dived down to the bottom of the pool, lake, pond, and sat there on the bottom, you'd have unlimited air.
NOT!
It was a nice fantasy, though. Maybe 18"?
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Post by nikeajax on Mar 20, 2018 13:18:05 GMT -8
It’s my understanding that the medium bore snorkels are optimal for most people, in that it has to do with lung strength and capacity. Because it’s easier to move a smaller amount of air than it is a larger amount of air, the air can moved faster, but if it’s too small, too much exhalation effort is required to expel the gasses. Furthermore, it doesn’t take much added volume to degrade the efficiency and a significant proportion of more energy is needed to expel the gasses at an acceptable rate for the body to recover.
I sent Eb a White Stag big-bore snorkel I had because I just couldn’t get enough air into my lungs while trying to swim with it, but my slightly smaller Dacor snorkel let me breathe much more naturally.
Another way to look at it is carburetion: if the motor’s engine is getting too much air, rich-mixture, the motor quickly fouls the spark-plugs, or if the mixture is too lean, the combustion chamber will get too hot and burn up the electrodes of the plus, and even burn a hole in the top of the pistons! But if you optimize the flow of air, the efficiency of the motor rises dramatically.
I hope this make sense?
JB
PS I didn't know that Mr. Hawking was as young as he was. I think because he had such a drastic disability the world noticed him more than they would of a more neurotypical scientist: it was a double edge sword.
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Post by DavidRitchieWilson on Mar 21, 2018 1:50:36 GMT -8
I mentioned earlier in this thread that I had researched national standards relating to snorkels. Having done so, I came up with a summary table showing how snorkel specifications, in particular the dimensions of barrel length and bore diameter, have changed in response to the development of scientific knowledge and concerns about health and safety: These are my observations: - Maximum tube length has almost halved (from 600 to 380 mm) over the years.
- Maximum bore (inner diameter) has increased (from 18 to 25 mm) over the years.
- Capacity (or inner volume) has replaced inner diameter when dimensioning snorkels over the years.
- Different snorkel dimensions have evolved for different users over the years (first adults/children; then heights >150 cm and <150 cm; then individual lung capacities).
- Mouthpiece parameters are specified in earliest standards but not in later ones.
National and international standards on snorkels have been around for almost half a century. Sadly, only a minority of snorkel manufacturers choose to reference these standards and the majority don't even state whether any particular model of snorkel they manufacture is designed for adults or children. DRW
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Post by nikeajax on Mar 21, 2018 8:34:54 GMT -8
DRW, this reminded me of shoe sizes, and how important that is to everyone, but then, I thought about Buster Keaton, who was very famous for wearing "slap shoes": JB
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Post by SeaRat on Mar 26, 2018 8:27:50 GMT -8
I am going to start discussing snorkels that I have and have been using/testing over the last two weeks. The first two are the ones I have used forever, almost. This first snorkel is perhaps the best snorkel ever developed. It is the U.S. Divers Company Impulse snorkel. It is a "dry" snorkel, because it has both a bubble on the top and a collection area with a non-return valve in the bottom. But, unlike most of today's "dry" snorkels, it does not cause any restriction of air flow. The bubble at top is actually a flanged surface with a non-return valve below, that allows any water entering to go out the snorkel without going down the tube. It uses water's capillary action to action... More later, as it is now "walk time" for Chris and me...I'm back, and we walked two hours, with my iPhone "Health" app saying we did 4.8 miles, and 12,996 steps, climbing 3 floors. Chris and I do something each day, either a walk like this, or going for a swim, or if the weather is nasty we do inside training on an elliptical trainer or my recumbent bike trainer. We try to stay in shape for getting outside for our hikes, canoeing or my diving. Now, back to Chris' mask and snorkel. She has a TUSA HyperDry mask now, as she had problems in the 1990s in Hawaii keeping her mask dry. This mask, with the combination of the Impulse snorkel, seals for her; I'll explain in a bit. Here's a closer photo: It is hard to see in these photos, but Chris has these wonderful smile lines on her cheeks, and that became a problem when choosing a masks/snorkel combination. We found that the Impulse snorkel, with it she large and wide mouthpiece, erased those smile lines and created a water-tight seal with the mask skirt on her face. Here is what the 1993 "Golden Anniversary issue of U.S. Divers Company catalog stated about the Impulse Snorkel: We have two, a red and a blue one. I bought both for our trip to Hawaii in 1993, and they are still almost like new, having been used for these years. Chris now has both, as the snorkels with a smaller mouthpiece don't rephrase those smile lines, and her mask then leaks. John John
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Post by SeaRat on Mar 26, 2018 16:50:43 GMT -8
Okay, here's my second mask/snorkel combination. It's a Swimaster Wide View mask with a Scubapro snorkel that is the older style snorkel. It is called a "Jet" snorkel, as it has a contoured barrel. Ya, that's me. I'm lookin' too old to do this stuff, but I'm still in the water. And this is me under the surface on the mask and snorkel. I swam laps with this combination, and had no problems at all. This is a wide tube snorkel (no measurements yet) and cleared easily. If I had any water in it, I could clear it simple with a forceful exhalation. No whistles or gimmicks. It cleared best by displacement (pointing the snorkel down as I surfaced and exhaling, allowing air to displace the water as I came to the surface. I did several dives to 15 feet too in the deep end after Chris was done with her swimming. The mask functioned fairly well, but I prefer (or actually my ears prefer) to use a nose-pinching method for clearing rather than the nose-blocking method that this mask offers. On the plus side, it clears really easily, and is pretty comfortable in the water. I'm using the strap that Jaybird sent to me several years ago, and it works well too (the original strap is gone). e John
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Post by SeaRat on Apr 1, 2018 15:39:14 GMT -8
I have done quite a bit more in-pool research on snorkels. I have a photo of a smaller-diameter snorkel, but in this photo unfortunately you cannot see the 90 degree bend at the top of the snorkel. When I first used it, I used it on my left side, and that resulted in cleared water being directed straight forward from that 90 degree turn. That was not so pleasant, as it resulted in a kind of bubbling experience. So my "fix" was simply to put it on the other side of my mask. Here's an underwater photo of it: Now, when I surface it clears nicely rather than against the flow of water, and I did not find the snorkel too hard to breathe through, even with the smaller diameter. But then I went back to my basic oval mask (in this case, a White Stag mask), with a Scubapro Jet Snorkel. This snorkel has a larger bore, but no whistles or gadgets. It was easy to clear with the displacement method too. I found that if I had some water in the snorkel, just a couple of hard breaths would expel the water, no non-return valve needed. Finally, I went back to my Scubapro three-window mask, and had a great experience with it and a Dacor flexible silicon snorkel. This snorkel is one of my favorites, both because it is flexible and out-of-the-way for scuba diving, and because it clears easily, having a smooth interior. Note that the snorkel is made so that it won't fold over on itself in a high current situation. I don't really like this photo, as it makes me look not only old, but somewhat scary. My eyes are a bit irritated from both the chlorine in the pool and also the anti-fog I used in the masks (third mask for this pool session). It gives a great view of my face, but you really need a more handsome or pretty face behind the lens. John PS, note the mask print on my forehead from the previous, Dacor low volume mask in the second photo above (wearing the White Stag oval mask).
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Post by Aquala1 on Apr 1, 2018 19:43:18 GMT -8
I’ll have to take some measurements tomorrow, but the best snorkel I’ve ever used is the little Healthways snorkel that I posted in the “Healthways Peripheries” thread. I’ve had all types over the years, and the small diameter of the barrel clears easily and I don’t feel like I’m rebreathing too much Co2.
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Post by Aquala1 on Apr 2, 2018 7:21:51 GMT -8
Total length from opening at mouth to the opening at top is 525 mm (20 11/16”). The bore diameter is 17 mm (11/16”).
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Post by Deleted on Apr 2, 2018 8:28:07 GMT -8
Flickr isn't allowing me to log in right now........but I have only really used two different types of snorkels in 51 years on and off of diving. The first was a SW snork-L with a 16 or 19 inch barrel.....long sucker and it was hard to inhale but I was young and didn't know better.......skin dived all the time in Okinawa with it and for several years after state side, until I cut the sucker down to 12 inches. Too much I reckon as it kept drawing water when I looked at any angle other than 45 degrees forward. So I bought a new one........USD Power snorkel......it was great to breath through. Had the same bore as the snork-L but with a flared end, that according to the University of Texas science dept. allowed maximum air flow, minimum resistance, both in and out.............lost it in the Gulf of Mexico in 2005 diving the Flower Garden reefs.........saw that Dan had three for sale and I bought all three.........exwife took one in 2006, leaving me two. I have no need for another type as I am satisfied with the Power Snorkel. I did get my new wife of 8+ years a clear plastic (slightly larger bore)with her first mask.
I stopped diving with a snorkel attached to my mask after Oki and to my body after losing one in the Gulf. Easier to just roll over on my back and leisurely swim to the boat or shore.
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Post by Aquala1 on Apr 3, 2018 5:16:01 GMT -8
I stopped diving with a snorkel attached to my mask after Oki and to my body after losing one in the Gulf. Easier to just roll over on my back and leisurely swim to the boat or shore. Same here. I was initially trained to scuba with a snorkel with the thought that if you ever found yourself on the surface during rough conditions, the snorkel would somehow help. Of course PADI required it, but it also gave the dive shop one more item to sell, and helped the shop owner promote a ranking system he devised. It was bands of different colored tape to distinguish levels of training. On scuba, I always found them to be in the way. Something to pull on the mask causing it to leak. Maybe it would come in handy on the surface during rough conditions, but I’ve dove in some pretty rough stuff, and have never wished I had a snorkel. Now if I were doing a lot of shore diving, with a long surface swim to the dive site, then maybe. Even then I think I’d rather flip over on my back, and occasionally look over my shoulder to make sure I was still on target. I love snorkels for snorkeling, but I don’t see where they have much application for scuba. For you guys who still scuba with a snorkel, is there a benefit that I’m missing?
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Post by cnotthoff on Apr 3, 2018 9:31:00 GMT -8
. So I bought a new one........USD Power snorkel......it was great to breath through. Had the same bore as the snork-L but with a flared end, that according to the University of Texas science dept. allowed maximum air flow, minimum resistance, both in and out.............lost it in the Gulf of Mexico in 2005 diving the Flower Garden reefs.........saw that Dan had three for sale and I bought all three.........exwife took one in 2006, leaving me two. I have no need for another type as I am satisfied with the Power Snorkel. I did get my new wife of 8+ years a clear plastic (slightly larger bore)with her first mask. I stopped diving with a snorkel attached to my mask after Oki and to my body after losing one in the Gulf. Easier to just roll over on my back and leisurely swim to the boat or shore. I dove the USD Power Snorkel for years. It was described to me as the same technology as Holly Carbs. Certainly felt that power surge. It finally just rotted away. My family is headed to Okinawa this fall. Any suggestions on places to dive? We plan to dive with Reef Encounters. Good Dives, Charlie
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Post by SeaRat on Apr 3, 2018 14:31:46 GMT -8
Yes, I use a snorkel all the time. The one time I decided not to, I was diving my Overpressure Breathing regulator in the Clackamas River, went out into the current, took a breath, and all I got was water. Tried a second time, water again. Surfaced, grabbed some air from above water line, tried for my snorkel but remembered I had not dived it that day. Grabbed another breath, found an eddy in the current behind a rock, and swam to shore. I went up to the car, changed regulators, grabbed my snorkel for the oval mask, and went diving again. Last summer, on my lamprey dives, the second dive I was videoing the lampreys spawning, and stayed an extra minute or two after pulling my J-reserve. I surfaced, switched to my snorkel and swam the last 100 or so yards downstream to my exit (you can google "Lampreys Spawning--Two Dives" and see those dives). There are some really beautiful shore dives on Okinawa. I was stationed there in 1968, so my experiences are a bit dated. But here are some photos: This is on one of the north shores, and we dove within the reef. Looking down on the diver, I wore twin 42s, while the rest were diving twin 72s. These were my Pararescue buddies, Terry Wetzel (center) and Stephen Samo (right) diving within the Okinawa reef. Terry passed away just this year, and I went to Florida to see him last spring, feeling that I needed to see him soon. He had lung and brain cancer at the time. Looking at Google Maps, here's a part of the northern side of Okinawa. Note that there is now an aquarium there, and note too the reefs. This is some of the best warm-water diving I have ever had! John
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Post by Aquala1 on Apr 3, 2018 15:38:47 GMT -8
Good stuff, John. What happened to the Overpressure Breathing to make it breathe wet?
Okinawa looks incredible! I wonder if the reefs are in as pristine condition today, as when you were there in ‘68?
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Post by Deleted on Apr 3, 2018 15:47:48 GMT -8
Diving Okinawa today I suspect will be different than when I or even John were there. I belong to a US Marine veteran group on facebook and have seen recent photos taken by today's Marines.......John, the place is really built up.....the Japanese have been very busy since they were given the island back. Most if now all the outer smaller islands are now connected via a two lane bridge like the old one that ran down the Florida islands. And I understand that there is a submerged structure on one of the smaller islands. There are probably many places unknown at the time to me that the Japanes have found......they are big on diving.
Most of my diving was off the Marine bases......Swab, Hanson but there may still be the Horseshoe open, between the air force antenna farm and a small village *probably a big village now......it is on the north side as well as Monza beach..wear gloves at Monza beach because if you get caught in the out going tide, it is hand over hand over the coral to get back..out going current is really stiff......if you can find and dive the horseshoe, go to the right along the cliffs until you see a huge cave above the water line.....easy to enter if the tide is out, shallow flat reef rock up to it, but tricky getting into with tide in. You have to judge the waves also getting out of the cave at high tide, swimming like hell between the sets....directly inside should still be a huge rock in the center then inside again to the right it is cut back about a hundred yards......at the very end there may be still a repository of every shower shoe (flipflops) ever lost in the Pacific. And take a dive light.....it is black in there until your eyes adjust.
On the southside near the Marine bases is Kinville.......the beach areas long there are shallow sloping but end in really nice coral reefs. If your wife is going and if you have daughters, keep an eye on them. Most of the Marines will have not seen a round eye girl in many months.
Also, John is very correct about the diving......best warm water I ever dove or snorkeled......more snorkeling than diving I think...better than Cozumel....fantastic collection of marine life. I remember sea urchins the size of soft balls with spines near 3 feet long.
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