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Post by nikeajax on Mar 11, 2014 8:55:44 GMT -8
So, what's your favorite: why?
Jayb ird
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Post by SeaRat on Mar 11, 2014 17:33:57 GMT -8
So, what's your favorite: why? Jaybird Jaybird, First, let's look at the science of vision underwater. Here are several drawings which show range or field of vision for different masks: This is the Scubapro Catalog which shows the Supervision mask, which is one of my favorites. (Human Performance and SCUBA Diving, Proceedings of the Symposium on Underwater Physiology, Scripps Institution of Oceanography, La Jolla, California, April 10-11, 1970, Cy Yttri, Director of Publications, The Athletic Institute, SBN 87670-805-X, Chicago, page 8.) This shows the field of vision of the oval, kidney and recessed kidney masks, along with examples. This diagram shows the fields of vision of the tri-window verses the regulator masks. (AMF Voit Catalog, as I recall.) My favorite masks depend upon my activity. In high current, I like close-fitting masks which will take the current without displacing. For years, especially in cold water, I liked the Scubapro Supervision, but then got a Farallon tri-view and it became my mask until it too melted off my face (a problem with neoprene masks over the years). Now, I like black silicone masks, as they don't "melt." Also, I am using the SeawiscopeEY, and so like that Dacor mask as it give me the best use of that device. The SeawiscopeEY has revolutionized my observations of very small underwater critters, so the mask I choose now must be able to fit the SeawiscopeEY (most do--the oval with the metal band and screw on the top are a problem for mounting that device). If I am free diving, I choose a low-volume close-fitting mask for displacement of air when I go deep, but I haven't done much of that lately. I have pretty much rejected some, such as the newer Scubapro tri-window at the top row, as it actually has a blind spot between the side and front window. This is because the windows are at 90 degrees. You get really good peripheral vision, but have to be aware that something can move out of the periphery and into the blind spot before you can see it in the front lens. John Attachments:
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Post by nikeajax on Mar 12, 2014 8:48:36 GMT -8
John, thanks for your input. I keep thinking this could have an application in diving masks: en.wikipedia.org/wiki/Gorilla_Glassespecially in a low volume mask that could wrap around like sunglasses. The low volume mask I used, sorry, I can't remember which, really hampered my vision. The frame was a very bad blind spot: not unlike the posts on the turret(top) in an automobile. In the mid 1950's, and early 1960's they started using wraparound windshields: as can be seen on my car here: About a year ago, in my '98 Toyota pickup, I was at a stop, and started to go when it was all clear: well it wasn't, there was a child hidden in the front post of the truck!!!!! When we were in Belize diving, I couldn't keep track of my wife because I had no peripheral vision: when we got out I told her, "NO, NEVER AGAIN, we'll never dive without a wraparound mask..." Jaybird
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Post by SeaRat on Mar 13, 2014 10:27:53 GMT -8
Jaybird,
The problem with wrapping glass around is distortion. U.S. Divers Company tried that in their first wide-vision mask, and it had problems in the "wrap" area. I did a test on a Scott SCBA full face mask that has a curved lens, and that caused it to have a 180 degree field of vision; it was like looking through a fisheye lens and trying to make sense of what was there. The Scubapro Supervision came closest to getting it correct with the angle of the lens (see the AMF Voit diagram above).
I know exactly what you are saying about the pickup and the car hidden in the post; I had that experience recently. I almost stopped in time, but nicked the rear bumper of the car with my front bumper--cosmetic damage only on both vehicles. But I took the hit as the other driver had the right-of-way on a street I was attempting to enter.
John
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Post by nikeajax on Mar 13, 2014 10:44:26 GMT -8
DOH!!!!! A week ago I saw an auction on ebait, and last night I thought, "Oh, what the h**l, I'll just place a bid for the lowest..." well, I won, and was the only bidder too! What did I get: a Healthways Gold Label, a Nemrod Snark III, a USD knife, a USD tank gauge, and a Sherwood wrap-around mask: dumb luck I guess I'm not complaining mind you, it's just that I honestly didn't think I'd get it is all. More later, Jaybird
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Post by diverdon on Mar 13, 2014 17:00:41 GMT -8
Sounds like a nice score Jaybird. Only bidder huh? Now,why didn't I see that auction..? Well congrats!
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Post by sitkadiver on Mar 13, 2014 17:55:27 GMT -8
Definitley a nice score. I saw the auction and thought it was a good deal for the two regs. The gold label looked to be in good condition also.
On the subject of reounded lenses: The firehall used to have AGA SCBA's and when they switched to Scott Paks, they gave all the AGA masks to people who wanted them. (I ended up getting one to convert to diving.) The fire fighting masks had a rounded lens that really gave people vertigo underwater. I know of at least one guy who tried to swim with his SCBA converted mask and ended up sea-sick.
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Post by nikeajax on Mar 13, 2014 18:20:16 GMT -8
Dave, you've got a coup'la boxes headed yer way buddy!
Thanks again, Jaybird
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Post by nikeajax on Mar 14, 2014 12:37:24 GMT -8
What I'm thinking of is more like old aviator goggles: With the extra strong glass, you could bend a solid piece of glass thus eliminating the barf-effect: this would be done with the glass still hot of course. It would also get rid of that NASTY blind spot... I've noticed, sorry, changing the subject here, that on some of the Nemrod/Seamless gear, they have what looks like a small float attached to the yoke: what the heck purpose dose that serve?!?!?!?!? Jaybird
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Post by nikeajax on Mar 14, 2014 16:53:30 GMT -8
Been trying to geek out about my Nemrod Snark, with very little success, but what I was able to find out on that other site, is that Juan Vilarrubis was very much into rocketry... So putting two and two together I realized something... As a few of you know my nom de plume "Nike Ajax" is a very old guided missile: A Snark is also a very old guided missile: There was also a regulator called, are you ready... Kinda interesting, eh? I knew about the Snark missiles, and kept thinking, "Gosh, could it be, nawwwww...." Jaybird
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Post by regulator68bj on Mar 14, 2014 18:33:57 GMT -8
Hi nikeajax ,
Just spotted these and as they are in "Nemrod" "Snark 11"House colours just great to "Chill" after dive.
john
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Post by regulator68bj on Mar 14, 2014 18:44:39 GMT -8
Oh nearly forgot the cork floater attached to the yoke HP inlet cap it's so you can quickly find it in the dive bag after the dive.
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Post by nikeajax on Mar 25, 2014 10:33:50 GMT -8
As promised, here's my Nemrod Snark III: It was missing the yoke screw and aluminum dust cap, so I took it off of my Delta. I'm going to put a tee where the over pressure valve is and run the second stage of the Delta, the second stage will act as an OPV, and BC hose! I'm also going to use John's trick of making a deflector, as the air coming out can cause feedback as it hits the diaphragm... Speaking of which, all of the diaphragms are still good! A Mistral's diaphragm will work on these, but that monster-big exhaust valve is next to impossible to find... Jaybird
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Post by nikeajax on Mar 25, 2014 10:38:24 GMT -8
Oh, and a Delta is yet another missile! Jaybird
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Post by sitkadiver on Mar 25, 2014 14:18:29 GMT -8
Jay,
Have you been to the Nike Museum by the Golden Gate? I've only read about it. Do they have a missile exhibit there?
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