Diving Performance - Beyond Drag (article Series And Discussion)

[ronscuba]

I dive warm water and shoot video. Streamlining helps me swim faster to get to and stay with marine life. Depending on the location and dive conditions, I will bring additional gear that creates drag. Snorkel, SMB, whistle, light, backup light, noisemaker, etc.. It's a trade off.

I definitely can see scuba gear and divers getting more streamlined. Maybe even seeing dolphin kicks on a regular basis. Monofins in mainstream scuba ? I doubt it. I think it would limit fine tuned movements that photographers and videographers need.

Padi certificate ? Ugh, Put Another Dollar In. Some of the PADI specialty courses are ridiculous. If I were going to take a freediving class, I would not choose PADI.

 

[REVAN]

Now, question for the OP. When I'm lugging my large camera around, I'm holding onto it by the most part with both hands. It introduces a lot of drag, so much so that I was once left in the dust by my dive buddies (we were floating in the green so nothing for me to shine my light on for them to see). I noticed in the video that you use your hands a bit. If those are not available, how easy is it to maneuver? I don't see how you would back fin or helicopter turn.

For the most part, I am also holding onto my cameras with both hands, but I designed it balanced so that I can hold it effectively with only one hand when needed (a nice feature that's lacking with most underwater camera systems). In the above video, I had 2 video cameras on a 4 foot wide boom. Sometimes, I have a third camera for stills mounted as well, but I don't remember having it attached on that dive. It was a tight fit to get that wide assembly through the narrow crevice in the rocks and I was approaching it very fast. My cameras are mounted out at the ends of the boom to get the desired perspective angles, so you can see why I'd slow down and invoke a little extra care to not crash them into the rocks while maneuvering through such a tight space.

Personally, I never feel that my maneuvering is inhibited when using the monofin. On the contrary, I feel like I am actually more maneuverable simply because I can get about so easily. But, I don't back fin with it. I've never needed to. I can do like the fishes and use a pectoral to back up, or just go around and try again. The monofin is not the fin to choose for sitting on the bottom doing nothing but macro photography, nor would you choose it if you were a commercial diver working on a static divesite. It's made for moving. Maybe that's not for everyone, but it can be a lot of fun.

 

[wetb4igetinthewater]

For the most part, I am also holding onto my cameras with both hands, but I designed it balanced so that I can hold it effectively with only one hand when needed (a nice feature that's lacking with most underwater camera systems). In the above video, I had 2 video cameras on a 4 foot wide boom. Sometimes, I have a third camera for stills mounted as well, but I don't remember having it attached on that dive. It was a tight fit to get that wide assembly through the narrow crevice in the rocks and I was approaching it very fast. My cameras are mounted out at the ends of the boom to get the desired perspective angles, so you can see why I'd slow down and invoke a little extra care to not crash them into the rocks while maneuvering through such a tight space.

Personally, I never feel that my maneuvering is inhibited when using the monofin. On the contrary, I feel like I am actually more maneuverable simply because I can get about so easily. But, I don't back fin with it. I've never needed to. I can do like the fishes and use a pectoral to back up, or just go around and try again. The monofin is not the fin to choose for sitting on the bottom doing nothing but macro photography, nor would you choose it if you were a commercial diver working on a static divesite. It's made for moving. Maybe that's not for everyone, but it can be a lot of fun.

I have an Aquatica 5D Mark III housing for my Canon. It is a bit of a beast, but it has to be with that large of a camera. I clip it off when I shoot a DSMB, but otherwise, I'm holding onto it. I do have to backfin sometimes when teaching. But I will say, the monofin is an interesting idea. I'd like to see how far I could go on a single tank of gas. In summer, I know just the place where I'd like to try one. Just when I'm diving for fun.

 

[fjpatrum]

I would appreciate your elaborating on this statement. Are you saying that you think my proposed working requirements are off, or are you referring to something else?

I mean I don't believe "drag" is remotely essential to diving in 9999 out of 10000 dives, probably even less than that. I also don't believe there are more than a handful of dives in the world where a 3 knot sustained speed would be necessary and certainly not a 5 knot sprint. (To my knowledge all such dives are done as drifts, which is not a problem for most divers.)

I disagree with your basic premise, as I said in my first or second post on this thread and in other threads.

Similarly, I believe it has been shown quite successfully in the other threads that the drag created by scuba gear is just a small portion of the drag of the diver as a whole and that incremental changes in this have very little impact on overall diving "quality" except in free diving where speed matters. On scuba speed simply doesn't matter for almost all people. In fact, many divers want the opposite of speed. They want to stop. They want to hover, look around and enjoy the scenery. This simply can't be done practically using a mono fin.

As another poster indicated in this thread, how does one helicopter turn, back fin, or successfully perform a non-silting kick close to the reef, sand, whatever, while using a mono fin? It simply can't be done while still also benefitting from your supposed efficiency.

I don't agree that your premise is suited to most divers, simply put. I think your requirements are not only off, they're completely misguided for most scuba divers. If your market is free divers, you're spot on, but most scuba divers simply aren't looking for speed.

 

[ronscuba]

.....

I don't agree that your premise is suited to most divers, simply put. I think your requirements are not only off, they're completely misguided for most scuba divers. If your market is free divers, you're spot on, but most scuba divers simply aren't looking for speed.

I respectfully disagree.

Being more streamlined can benefit all divers. Ever dove in current or do drift diving ? Ever had to hold your position against current because a member of your dive group fell a little behind ? Being more streamlined also helps with air consumption. Having the ability to go fast does not mean you always have to swim fast. It's there when you need it. Are you interested to see and dive with whalesharks or other large marine life ? Guess what, you will want the ability to go fast.

The article does have some wording that could be considered derogatory towards tech and scuba divers and that is a shame. This should not be a tech diver vs scuba diver vs free diver argument. There are certain aspects of gear choice, configuration, technique, from each, that can be beneficial to all.

I am a recreational open water scuba diver. I have taken some gear configurations and setup from tech diving and free diving because they benefit me and the way I dive. I am not alone. I see others doing the same on dive boats.

 

[REVAN]

I mean I don't believe "drag" is remotely essential to diving in 9999 out of 10000 dives, probably even less than that.

I invite you to browse this ongoing thread right here on SB: What's the most intimidating dive you've done or thing that happened to you?

I have not taken the time to do a detailed survey of the thread, but when I was reading through these posts the other week, it seemed that at least 2/3 of the cases listed were of people writing about problems dealing with currents. If you are diving in the ocean, currents are an issue. People have died resulting from a confluence of stronger than anticipated currents combined with some poor judgement.

The crux of normalization of deviance is it seems that it doesn't matter, until it suddenly kills you. This dangerous pattern of thought has brought down 2 Space Shuttles, and it can kill divers also.

After a major accident, a careful analysis will show that the warnings were there all along, but everyone ignores them as just being normal. Take the example of all the reports of intimidating dives resulting from currents and ocean conditions in the thread listed above. Instead of recognizing there is a problem that should be dealt with, everyone just takes an attitude that you aren't a serious diver until you've had your ass kicked by currents. It may be common, but it is not right.

If you think my proposed requirements are way off, what minimum mobility requirements would you propose for a manned diving system operating independently in the open ocean?

 

[fjpatrum]

@ronscuba, that's reasonable. Your experiences are certainly different than mine so having a different perspective is warranted. I ask you though, how often is a group separation the result of inefficiency? How often will it be overcome by these "improvements"? Will it be enough to give up what you're losing? I don't think it will.

Streamlining is all well and good but the math doesn't support these "efficiency" gains, as has been indicated by several different people in other threads that generated this discussion. The drag numbers OP has come up with don't match anyone else's. Why is that? What is different in his assumptions and test set up than all of those who've come before him? Are they all wrong or is he missing something?

I don't get "separated from my group" because I don't group dive, simply put. I buddy dive; I go where my buddy goes and hopefully they go where I do. As such I don't generally have to "catch up", though it has happened once or twice. I personally still wouldn't make an equipment change for a skills deficiency in that regard. (Be it my skills or my buddy's.)

Like you, I wear a more "tech-like" gear config but putting on a different fin with far more limited kick options isn't going to help my diving, nor will it for most people, in my opinion. Especially people who want to stay still, or move backwards. Will it help conserve air? Maybe. Will it conserve enough air to be worth the effort? The math says not likely if efficiency improvements in drag are all we're talking about. It is more likely to reduce fatigue a little bit and that is a good thing in my opinion. Still not enough to convince me (yet) a monofin is the right choice.

I have snorkeled with the whale sharks. Yeah, I had a hard time keeping up. If I were on scuba, though, I wouldn't have needed to "keep up" the same way because I could have gotten wider photo shots from different angles more easily than I could from the surface. That is one of a "handful of dives" where I admitted (in my last post) there might be some benefit from these kinds of improvements. Again, I wouldn't change my kit for every dive based on that one.

 

[fjpatrum]

I invite you to browse this ongoing thread right here on SB: What's the most intimidating dive you've done or thing that happened to you?

I have not taken the time to do a detailed survey of the thread, but when I was reading through these posts the other week, it seemed that at least 2/3 of the cases listed were of people writing about problems dealing with currents. If you are diving in the ocean, currents are an issue. People have died resulting from a confluence of stronger than anticipated currents combined with some poor judgement.

If you think my proposed requirements are way off, what minimum mobility requirements would you propose for a manned diving system operating independently in the open ocean?

@REVAN I've read the linked thread in its entirety. You are seriously over-inflating the problems people have with currents, based on what I've read in that thread and others like it. People being "intimidated by" a situation isn't the same as having a real problem with it. I also don't see any significant belief that "you aren't a serious diver until you've had your ass kicked by currents". Do people recognize it as an issue? Certainly. Would being able to swim at 3 knots, 6 knots, or 100 knots help the problem? Absolutely. So will learning how to deal with an unexpected current without panicking. I've been in rip currents (though no down currents) and yes I burned some energy escaping them but I see that as more of a training/skills problem than an equipment issue. Sometimes, perhaps it's a planning issue, which might lead down the path of different equipment choices but, for the most part, it's a skills issue.

I think that last part is the issue here. You, as an equipment designer/seller, want to sell an equipment solution to what I (and many others) see as a skills problem.

To answer your requirements question, I would take a reasonable average of the currents at say, 90% of dive sites world wide during "peak" season (for each site) as the more realistic current requirements for a diver. I would then consider that there are very few divers operating "independently in the open ocean" and factor that into my estimates. (Most recreational divers in the "open ocean" have some sort of surface support, whether it's a buoy, a boat, or something else.) My complete guess is the number is closer to 1.5-2 knots than 3-5 knots but it is, admittedly, a guess.

 

[ronscuba]

When current/drift diving, the boat is following the group, which is why staying close together is important. Slight separation is normal as divers will explore, take pictures, shoot video, etc.. There is a need to fight current to maintain position to allow the group to stay relatively close together. It is kind of common for divers to take turns holding up the group a little.

I have not read the other threads you mentioned and I am not a fanatic about minimizing drag or pushing monofins. I agree that we each have to choose gear and configurations that best suit the type of diving we most frequently do.

I frequently see dive boat staff using long freedive fins. Making slight changes in gear choice or setup to be more streamlined doesn't have to be difficult or expensive.

 

[dumpsterDiver]

I think the whole normalization of deviance theme is a little over the top. Being able to swim fast is dependent upon the gear worn, the diver's physical capacity (endurance, strength and technique) and the type of fins. Few scuba divers need to swim fast a lot, but it does provide a buffer to handle emergencies or challenging situations.

I think a more readily accepted theme might be efficiency. How far can the diver cover with a fixed amount of air.

Drastic increases in speed are going to cause more losses to drag and at some point are going to cause a significant increase in respiration demands (drag is exponential with speed).. wearing a couple extra smb's or a pony bottle doesn't make that much difference in drag If you move slowly.

The general scuba diving public is too fat, too old and too out of shape to want to be swimming around, busting ass and blowing through their air on a normal recreational dive. Extremely vigorous swimming can also get you bent if you don't scale back time and depth.

The inability to swim backwards is the most minor of concessions, issues with getting in and out of the water with a weird mono-fin are probably much more of a constraint and will be far more common.

There is no way an old fat guy is going to swim 3 kts in a full scuba outfit without being winded and exhausted within a very short time. Scuba divers ATTACK the huge challenges of "trim", carrying a minimum of lead and reduced SAC - they are not interested in aerobic efficiency, physical stamina, speed swimming or 2/3 of what is being "sold".