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Post by scubalawyer on Jun 5, 2019 17:00:55 GMT -8
Scubalawyer- Hang on to those bio fins. Years from now somebody may change what we refer to as vintage. More than half of my equipment was "state of the art" when I bought it. Now its vintage and according to many LDS's unsafe. Go figure Didn't you know that dive shops consider all dive gear unsafe if it's more than a year old (six months if you didn't buy it from that shop)?  M |
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Post by nikeajax on Jun 5, 2019 17:31:42 GMT -8
As I've never used split's, it's my understanding that they're easier on your hips but don't provide as much propulsion, yes, no?
Jaybird
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Post by SeaRat on Jun 5, 2019 17:37:51 GMT -8
Scubalawyer- Hang on to those bio fins. Years from now somebody may change what we refer to as vintage. More than half of my equipment was "state of the art" when I bought it. Now its vintage and according to many LDS's unsafe. Go figure Didn't you know that dive shops consider all dive gear unsafe if it's more than a year old (six months if you didn't buy it from that shop)? M In that case, I have been "unsafe" for at least four decades.  Safety is relative, and some of the gear I see today will not stand up to a close inspection. I've been buying "new-style" masks at Goodwill for about $5/mask (for what sells in a dive shop for >$30). I had several of the "U.S. Divers" signature masks "die" in my hands last year. Why? Because the rod that they use for holding the strap against the adjusting lever is made of plastic. MADE OF PLASTIC!!! And not a robust plastic at that. The "vintage" masks that I have use these mask retainer/adjuster "D" rings with the rod inside, and the whole thing is made of stainless steel. The same with fins. The original Jet Fins, and the Lightning Jet Fins I've got, used a stainless steel adjusting mechanism that still works--from the 1970s! I've had several Mares fins, which I've used for my "scoop fin" design, buckles break, again because they are plastic/nylon/whatever! Take a look at the Jet Fin copies, and see what their buckle system is made of. If it's plastic, they simply won't last.  IMG_2456 by John Ratliff, on Flickr This is the plastic piece on the masks. Note that they broke with normal handling.  IMG_2455 by John Ratliff, on Flickr Here's what the masks look like that incorporate the plastic strap retainers. I use these only for pool work, as they do not pass my standards for open water work. So if someone chides you on using "old, unsafe gear," take a look at the masks they are selling, and examine this retainer. If it's not stainless, it will break, and is therefore not safe. I think this is why a lot of divers now carry two masks, one as a "backup." What they really ought to do is use one mask that is made to last. You can tell those dive shop operators that this comes from a former NAUI Instructor who has over 30 years in the industrial safety business, and has investigated serious and fatal accidents, including diving accidents. John John C. Ratliff, CSP(Retired), CIH(2006-2017),* MSPH NAUI #2710 |
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Post by scubalawyer on Jun 5, 2019 18:30:17 GMT -8
As I've never used split's, it's my understanding that they're easier on your hips but don't provide as much propulsion, yes, no? Jaybird I only have my experience with split fins to go by. Since water is not striking a solid surface (its "spilling" through the split) the force needed to kick on a downstroke is a lot less than, say, a rocket fin. However, you don't get propelled as far with each kick - but you can kick more times in a minute so you travel about the same distance with less force/ effort to yours legs. Hope that makes sense. There is probably a more scientific way to explain it but I ain't got that kinda book'learn'n. M |
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Post by nikeajax on Jun 5, 2019 18:41:56 GMT -8
I just can't stand modern gear--GRRRR! My biggest complaint is, like John pointed out, the masks. I think above all the mask is the pivotal piece of equipment that you need to be right: everything else you can limp by on. I'm a very visual person, and if I don't have my peripherals I can get disoriented fast.
JB
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Post by snark3 on Jun 6, 2019 11:55:44 GMT -8
I use allot of vintage gear. The old stuff just works. Some of these new fangled regs cost over a grand now, and nobody has been able to tell me one thing a new $1000 reg will do that my Conshelf won't. One of the guys in my dive club has one of those fancy new regs. When it started free flowing prior to a dive and he couldn't get it to stop he was ready to abort his dive for the day. I handed him my "backup" an early 70's Aquarius. He was horrified at how well it worked.
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Post by SeaRat on Jun 6, 2019 15:26:10 GMT -8
Here's one of my Pararescue buddies diving Jet Fins 1968.  PJ Okinawa Dive002 by John Ratliff, on Flickr Here's my fin collection a while back:  Fin Collection 10-2012 by John Ratliff, on Flickr I ran some tests of fins, and these are the results. I show them because there was a question about the efficiency of split fins. What I did was to use three pair of identical fins, one with a straight blade (Plana Avanti), one with a split blade (Plana Avanti with split), and one with my scoop disign (Plana Avanti with scoop modification). Here are the results:  Fin Trials by John Ratliff, on Flickr These are the fins which I tested above. Each swim in the above chart was for 50 yards.  PlanaPlus Experiment by John Ratliff, on Flickr Note, the scoop modified fin looks different because there was a split in the toe area that I needed to cut out. That fin has split more, to the extent that I'll only use it in a pool. I'm probably going to remove the scoop portion and use it on the flat blade at some point this summer. John |
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Post by DavidRitchieWilson on Jun 8, 2019 8:52:59 GMT -8
 A Ukrainian version of splits (picture above) was first manufactured in Kiev back in autumn 2005. Here's a very rough translation of the Russian-language announcement at sanaris.com.ua/products/: "During the 2006 season, 'Kievguma' Open Joint Stock Company plans to enter the diving equipment market with three new fin models, the 'first swallow' being a new model in the 'Aquanaut' fin series called 'SUPER'. Recommendations by leading experts on scuba diving and consumer demand formed the basis for the development of these new fins. 'Aquanaut SUPER' is a modern fin design with a blade split in half down the middle, with dividers of water on the edges of the blade and with a toe opening and pull-tab, making for a comfortable shoe-type fin. Split blades greatly increase the performance efficiency of the fins. 'Aquanaut SUPER' fins allow the swimmer to reduce the burden on the leg muscles and the airflow rate by means of small rhythmic strokes, bending the knees. It is known that low stroke amplitude decreases water resistance and turbulence, allowing the swimmer’s body to glide smoothly. Closed-heel and open-toe foot pocket provides comfort and keeps foot secure. The rubber blend lightens the fins by 200 grams. The complex has all the positive changes giving the highest possible performance. The first batch of "Aquanaut SUPER" fins was made in October 2005." |
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Post by DavidRitchieWilson on Jun 9, 2019 2:21:13 GMT -8
 Returning to the picture above, I thought I'd reveal what I believe to be the identity of Fin No. 3, which is marked as Italian in origin. I think this model is the Cressi Rondine-S:     What makes this Cressi fin interesting is that it's not the first "vented" fin Cressi released. I'm talking about the Cressi Super Rondine fin. Here's an explanation from Cressi's US distributor Healthways:  Here's a picture of a diver wearing a pair of Super Rondines:  And here's a Super Rondine ad dated 1960:  The date is significant, as Beuchat's Jetfins were launched in 1964, four years after this Cressi Super Rondine ad appeared. I know Cressi's "blade flap" design differs from Beuchat's vented blade design, but it certainly makes me wonder whether Beuchat was influenced by Cressi's Super Rondine. DRW |
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Post by nikeajax on Jun 9, 2019 11:20:16 GMT -8
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Post by DavidRitchieWilson on Jun 11, 2019 6:57:55 GMT -8
Thanks JB! I might as well identify Fin No. 4 while I'm here. I believe this Greek-made model to be the Balco Hydrodyn:   The Greek manufacturer is known as Balco, Eurobal Diving Company, or Georgia Frydas, with an address at 10 Themistokleous, 13671 Acharnes. The firm makes basic underwater swimming equipment, including fins, masks and what is probably the world's last old-school snorkel-mask on sale:  DRW |
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Post by nikeajax on Jun 11, 2019 8:29:01 GMT -8
DRW, have you ever used one of those masks? Just wondering as they don't look like they'd be very easy to breathe from: as with snorkels there's an optimal size of tube for exhalation: it does look really boss though!
JB
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Post by DavidRitchieWilson on Jun 11, 2019 13:29:44 GMT -8
DRW, have you ever used one of those masks? Just wondering as they don't look like they'd be very easy to breathe from: as with snorkels there's an optimal size of tube for exhalation: it does look really boss though! JB  Never in the water, JB. The model in the centre above has surprisingly stiff sides and covers the whole face. I've tried it on, of course, and I was able to breathe through the nose and the mouth when wearing it, but the inside of the lens misted up quite quickly. I found the model on the left much easier to use because it's very light, the skirt is very soft and the mask only covers the eyes and the nose so I could breathe through the nose while leaving the mouth free. I guess these masks were a boon to those who gagged when they had a mouthpiece inserted in their mouths or who found separate masks and snorkels a bit too unwieldy and needed to use both hands for spearfishing purposes. DRW |
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Post by nikeajax on Jun 13, 2019 14:28:32 GMT -8
I was wondering about just how quickly they fogged up! That white one looks like it would really distort things to the point where you might get nauseous...URP! I remember John talking about using a SCBA used by fire fighters, but trying it under water:  Yeeehawww-- DISTORTION!
JB |
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Post by SeaRat on Jun 13, 2019 16:36:27 GMT -8
I was wondering about just how quickly they fogged up! That white one looks like it would really distort things to the point where you might get nauseous...URP! I remember John talking about using a SCBA used by fire fighters, but trying it under water: Yeeehawww-- DISTORTION!
JB "Distortion" wasn't the word; actually, the word was "vertigo"! I used a Scott SCBA in the water, and it initially freeflowed until I got horizontal, and got the waist-regulator level with the mask. But everytime I turned me head, I'd get another 180 by 180 degree movement, and it cause vertigo. It was not pleasant at all. I did this at the request of the Winston-Dillard Fire Department as a Safety and Health Consultant when we were setting up their river rescue team. I found that it was possible to use the SCBA in the water, but only for a very brief time and with the understanding of the visual distortion causing vertigo. One great outcome from this training was getting one of the members of the fire department to become an USAF Pararescueman in the 304th Aerospace Rescue and Recovery Squadron in Portland, Oregon. John PS, there is no fogging on the SCBAs, as the nasal mask prevents it. No exhaled air goes against the lens; this is not true of the new full-face snorkel masks now being sold--their nasal mask doesn't seal against the face. |
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M
