Question: Freediving vs. SCUBA and diver drag

[finSailor]

Freediving is living in a dream. Scuba is like driving a cement mixer to a construction site.

Love the quote! I hope it's open source

 

[Piotrek]

(...)
There is another factor that might be affected if you could make the drag similar. Can't quantify it very well, but free diving is just more "free" It feels better, more like flying(my childhood dream). Maybe reducing the drag would make scuba "feel" the same.

One can fly in scuba alright. The gliding part of flying in scuba very much depends on your kick technique, while the hovering part is dependent on your buoyancy control. Both are to a large extent dependent on the gear (and your ability to utilize its features, which is no small thing sometimes).

My freediving experience is limited to pools so far, and I love the feeling of gliding through water with minimal drag; I also expect this to get even better once I try open water. In scuba, I love the feeling of being able to stop and hang at any depth I choose, adjust it practically by centimetres, move in nearly any direction with a good amount of precision. But this can only come with training and is greatly helped by appropriate gear. Given the sweeping overgeneralizations above, let me just point out that "scuba divers" is not a uniform category, and most of the scuba divers one is able to meet, statistically speaking, will be of the "sport diver" kind -- nothing wrong about that, but at the same time one shouldn't compare people who put fins and BCDs on and jump into water for 20 minutes of fun with the amount of precision and awareness that is required for freediving. Compare freedivers with tech scuba divers -- that seems more fair.

As a tech diver, I fly like a bumble bee... ;-) It's slow, it's noisy (I dive open circuit), but it's also precise -- I can fit into that wreck hatch without ripping my drysuit, and I can move in a cave without raising the sediment (no flutter kicking, at least not in the way a freediver would do that), or I can simply hang in one spot. A freediver, from my limited experience, flies more like a swallow -- it's silent and it's swift, and graceful. But then, a freediver has to be gone within a few minutes, while a tech diver's time is basically only limited by the amount (and type) of gas. It's simply two different kinds of flying and both are super fun...

 

[Bill McIntyre]

But then, a freediver has to be gone within a few minutes, while a tech diver's time is basically only limited by the amount (and type) of gas. It's simply two different kinds of flying and both are super fun...

There is another way to look at it. I was a scuba diver for many years. In a diving day my actual time in the water was pretty limited by the amount of air and by no-decompression limits. Even if I exceeded no decompression limits, time spent hanging there decompressing was not exactly quality diving time.

As a freedive spear fisherman, I can spend all day in the water, limited only by my strength and endurance.

 

[Piotrek]

Sure thing, Bill, that's another way to look at it. Let me only remark that sports divers have greater time penalties than divers actually doing deco on oxygen, but still, your point is valid as well for the greater picture.

 

[REVAN]

Here's something to think about. Scuba divers don't have SWBs. It is not an issue for them. So, if you are off exploring, the scuba could add a good element of risk reduction for your diving.

I've been in conditions where I found being an effective safety was impossible because the visibility was less than the diving depths and I couldn't predict where they were going to be surfacing with error less than the vis.

If in the water, there is no real swimming penalty, in theory you could swim the same as you do presently while freediving. You could even do a lot of your excursion as a freediver breathing through the snorkel while on the surface and short dives on breath hold, but switch to scuba if you want to go down for more than just a short dive (maybe 30 sec. and up could/should all be on scuba instead of breath hold).

Looking at it from that perspective, could there be more interest in something like this from freedivers. Think of it like a FRV. Yea, it is more equipment to deal with, but it can not only reduce in-water risk, it can be useful in a non-emergency capacity as well. I think there may be something there worth considering. I might want to consider this as an opportunity to save lives of freedivers as opposed to finding a better way to scuba dive.

I think that is a DB member in the video you posted, I'm trying to remember his name, [ @rems doesn't connect to an account ]....

FYI - My memory came back. That was @sofabike in that video posted previously by @Chipswim, but it looks like sofabike's been off DB since 2011.

 

[Bill McIntyre]

Here's something to think about. Scuba divers don't have SWBs. It is not an issue for them. So, if you are off exploring, the scuba could add a good element of risk reduction for your diving.

There is no doubt that free diving is more dangerous that scuba, but I don't think wearing scuba while free diving will be acceptable to many divers.

I've been in conditions where I found being an effective safety was impossible because the visibility was less than the diving depths and I couldn't predict where they were going to be surfacing with error less than the vis.

Conditions like that are the norm in Southern California kelp beds. We just accept it. That's one reason why I wear an FRV.

If in the water, there is no real swimming penalty, in theory you could swim the same as you do presently while freediving. You could even do a lot of your excursion as a freediver breathing through the snorkel while on the surface and short dives on breath hold, but switch to scuba if you want to go down for more than just a short dive (maybe 30 sec. and up could/should all be on scuba instead of breath hold).

I don't know a single free dive spear fisherman who would even consider doing that. White sea bass like the fish in my avatar are notoriously sensitive to noise or bubbles. We take great pains to make a quiet surface entry. That would be very difficult wearing scuba gear. We make sure to get all the bubbles out of our wet suits because even small escaping bubbles can spook the fish. The squeak of equalizing pressure in our ears can spook the fish. I can't imagine how fish would react if I put a mouthpiece in my mouth and started blowing bubbles.

Another thing to consider. Free divers hold their breaths while ascending. That can be fatal for scuba divers. Trying to mix free diving and scuba diving could cause fatal confusion.

 

[REVAN]

If it were a rebreather, there would be no bubbles. It would be quiet. If noise was an issue, that could be one way to solve it.

Also, if you are on scuba you wouldn't be holding your breath.

Remember, I don't have any specific hardware in mind here. This is a thought exercise. For now, we should assume that whatever you want could be accomplished to at lease some level of functionality. The trick is to identify what you want. So many people are constrained in their imagination by what they are familiar with that they cannot even identify what they would want outside of that context. If someone had not gone through the trouble to make an FRV, would you know that you want one? If a scuba diver's BCD was the only thing you were familiar with for an underwater flotation device as a reference of context, you might think that freediving with a BCD in case you need flotation, sounds kinda silly?

We need to divorce what we know from what we need if we want to identify requirements for something new that can be useful in new ways. I'm basically working from the position that it might be possible to make some kind of a scuba system that can swim as efficiently as a freediver. If that is possible to do, is it useful? And if so, what other requirements would be imposed upon it for it to achieve that usefulness?

 

[growingupninja]

I am not a big fan of scuba, got my padi cert at 15 in a freshwater lake and have not done it since. It felt incredibly unnatural to me and I kept wanting to spit out my mouthpiece. I dont do the snorkel thing when I freedive/spear, either.

All that being said, I could maybe get onboard with that front mounted pony bottle set-up for really deep stuff, nix the bcd, why.bother as when freediving I am always negative amyways. You could hang a fullsize tank at 10M for deco stop perhaps?

But in general a super low profile, low drag scuba set-up is more interesting than the cement mixer type diving I see.

Rebreathers I also think are very intriguiging but again the redundancy systems tend to get very bulky.

My 2 cents.

 

[prospector]

Revan, has it occurred to you that freedivers already have all they need, if you can design me a set of gills like the fellow in water world, whip out the credit card. Cheers.

 

[Bill McIntyre]

Revan, has it occurred to you that freedivers already have all they need, if you can design me a set of gills like the fellow in water world, whip out the credit card. Cheers.

I think that sums it up. Revan, you seem to have a solution for a problem that doesn't exist. Even if it were possible to make some kind of a scuba system that can swim as efficiently as a free diver, freedivers would not want it. They want to free dive.

 

[REVAN]

It's sad, but puts things into perspective. If I do anything at all, I'll keep the project very small, with intentions of making something for myself only.

 

[Triton1715]

There is another way to look at it. I was a scuba diver for many years. In a diving day my actual time in the water was pretty limited by the amount of air and by no-decompression limits. Even if I exceeded no decompression limits, time spent hanging there decompressing was not exactly quality diving time.

As a freedive spear fisherman, I can spend all day in the water, limited only by my strength and endurance.

This is exactly why I switched from scuba to freediving. I love being in the water, but all the hassle to gear up, safety checks, surface swimming with cumbersome equipment, the noise it makes in the water, and then lugging it all back for just 45m-1:20 of dive time. I see so much more freediving than I ever did on scuba. Not saying that I don't still enjoy scuba, but unless I want to spend more time at deeper depths, there just isn't much that scuba offers me at the moment that I can't do freediving instead.

 

[Chipswim]

None of these are legit yet?.... Someday?

 

[growingupninja]

Ron, I had a chance to dive with some serious professional cave divers over the last week.

That community is always looking for more streamlined gear; the guys I worked with do not ordinarily wear BCDs but said they do have an air bladder to offset buoyancy of full tanks. They rig their tanks to be mobile so that they can change their body profile as needed; they are more concerned with entanglement than drag but same principle applies..

 

[andy2667]

Scuba and freediving are both very different experiences.
Expectations are also very different, and the people doing each are different.

To cut it short, being a freediver for about 10 years, I now practice scuba diving in a very different way. I breath much less; am more silent, swim much more efficient, and choose and arrange my setup with drag in mind. I wear long fins (Cressi Gara2000HF), use a 5mm nylon + open cell suit, carry no weights (my 15l tank was heavy enough), and wear a Sphera or Micromask. Thanks to this I'm faster and more air efficient then the others, using half of what they need. Also it made me realise that I only need a 10L or even an 8L tank to make no compression dives to 20-30m, which would again make my setup lighter and faster. Knowing freediving would influence my choice for equipment greatly! I would prefer to have low drag, but durable stabilising jacket, a low drag and resistance regulator, smoothskin sleeves, and pants, low drag computer, and tugged away console. All cool and fine, but...
The thing is that my buddy needs to be able to keep up with my speed and abilities. And you know that there are many overweight divers who love the carry properties of water, and avoid anything that might look like sport, because it makes them painfully aware of their physical short comings.
As a scuba diver I'm not aiming to make record distances. What I am looking for is nice animals, vista's enjoying the underwater environment and the fraternity of the diving scene.
Frankly I do not see much use in a mono for scuba; because the buddies cannot keep up, and it's unpracticality in manoeuvring in tight spaces on the bottom and surface. However Low Drag Gear (TM ) would be nice for scuba, especially in currents.
Navy Seals may find more use, infiltration and exfiltration (when speed and exhaustion is important) , if they also change their very draggy gear. I believe that the navy rather schedules a bit more time, then to teach the soldiers how to use the monofin, as swimming for some of them appears to be a challenge. (horrible scissor leg DNF's!)

For scubadiving I would love to have a silent, no bubble regulator, so I can enjoy the silence (cue Depeche Mode).

Hi Kars,

Understand that this is an old post. I am very interested in your experience in Scuba diving from an experienced free diver with the possible low drag in mine. I now just start to explore free diving and am very interested in reducing my drag and improving my efficiency in scuba diving. I have changed to use long free diving fins and the improvement in power, speed and efficiency is amazing. My next move is to change to use more flexible and efficient free diving suit, low volume mask.....

My biggest question is how to reduce drag from my BP/W. I am always wondering if a low profile jacket BCD is more streamline than even a low profile wing? Or a low profile BP/W like the Oxycheq 18lb be more streamline? Would be great if you could share your experience on this.

The other question is which long fins are most appropriate for Scuba diving in particular in handling current. I now am using Omer Stingray plastic fins. Always wonder if a higher end carbon fins will improve the efficiency and power. If I use carbon fins, will a soft fins of medium harness fins be more appropriate? I am not a big guy and with very limited leg strength.

Any other key points you would share on streamlining when scuba diving?

Thanks

 

[cdavis]

Andy, to the fins question. I've done a lot of scuba with longfins, stiff fins are what you need because of the extra drag of scuba. Soft fins work, used'em for years, but you will have to contend with one or more initial "empty kicks" where you don't go anywhere. The 2000hf that Kars uses is an excellent stiff fin for scuba, just be careful you legs can handle them. IMHO carbon or fiberglass won't help you much. A stiff fin is a stiff fin. If you decided that torque and acceleration were not important to you or you legs won't handle stiff fins, soft carbons can feel wonderful, but plastic is still a better choice. The efficiency difference is small and a good plastic fin (Cressi 3000ld for instance) is way more durable in a scuba format. FYI, I use fiberglass bifins or a Dolfin for freediving and Cressi 2000hfs for scuba. I'm very skinny, but with strong legs.

Kars will have some additional insights

 

[REVAN]

Hi Kars,

Understand that this is an old post. I am very interested in your experience in Scuba diving from an experienced free diver with the possible low drag in mine. I now just start to explore free diving and am very interested in reducing my drag and improving my efficiency in scuba diving. I have changed to use long free diving fins and the improvement in power, speed and efficiency is amazing. My next move is to change to use more flexible and efficient free diving suit, low volume mask.....

My biggest question is how to reduce drag from my BP/W. I am always wondering if a low profile jacket BCD is more streamline than even a low profile wing? Or a low profile BP/W like the Oxycheq 18lb be more streamline? Would be great if you could share your experience on this.

The other question is which long fins are most appropriate for Scuba diving in particular in handling current. I now am using Omer Stingray plastic fins. Always wonder if a higher end carbon fins will improve the efficiency and power. If I use carbon fins, will a soft fins of medium harness fins be more appropriate? I am not a big guy and with very limited leg strength.

Any other key points you would share on streamlining when scuba diving?

Thanks

You may want to consider using a BP without the wing. If you are diving in 3mm or less neoprene and doing recreational, non-decompression diving, lungs can usually be an adequate BC device. If you get your weight right and are good at using structured breathing techniques, you can have good buoyancy control during the dive and reduce your overall drag by up to 20%, simply by ditching the wing, inflator and LP hoses that come with using a BCD.

Have a read through my "Diving Performance - Beyond Drag" article series. You can access it through my website:
http://smithaerospace.us/technology/Research_Papers.htm

 

[andy2667]

Hi Davis,

Thanks for your advices on your experiences fins. You information is very useful.

Hi Revan,

Your articles are very interesting and inspiring. In fact, I have been intending to move towards the most streamline and most efficient fining direction. I have just started the baby steps you have mentioned in your articles:

Fins
Replaced by old trusted Mares Advanti Quatro last year by a plastic Omer Freediving fins because I was struggling in the current during my diving trips to Maldives and Komodo. Saw the DM using the Cressi Plastic Freediving fins with incredible power driven me for this change. Quite a big jump in improvement in power and efficiency. That is why I am now searching for more efficient fins for better handling current and more efficiency. May consider the better carbon fins if it is too costly. The mono type fins seems to be very efficient and tempting, but maybe beyond reach at my fining techniques and may not be that convenient during live aboard diving trips.

Your thought?

BCD
I use BP/W rings at the beginning of my diving journey. However, I choose the less efficient one, the Halcyon Infinity with 30lb wing. Use of STA is mandatory to fix the wing. Thus, the tank cannot be very close to my back. Also, the wing is a bit wide compared with the more efficient ones. I have been searching for my efficient BP/W with less drag but is not able to decide which one to choose yet.

Soft plate vs hard plate
- I think the Oxcycheq travel soft plate or alike is the most streamline backplate because it can warp around the back enabling the tank be the closest to the back. However, flat and streamline metal plate is very close to this configuration but the metal surface have less drag? Not able to decide

Hard Fabric wing or soft barricades wing. Overall narrower wing or .....
- After an extensive searching, I concluded that the Oxycheq 18lb wing might be the most streamlined wing (most narrow and smallest: 11.5"wide fully inflated and 21" long). However, its fabric is harder meaning that it cannot warp around the tank as good as other soft fabric wings. Is it s bad thing? The other choice is the Deep Sea Supply Torus 26. Only 12" wide fully deflated but 25" long. It uses soft fabric. Which one is more streamline??

At my diving level now, I may not be able to do wingless diving. I normally do liveaboard diving trips in warm water dive sites with some current. Deeper dives to 30+M. Wingless may not be the solution now but may try it if I dive locally in shallow and if the dive operator allow me to do so.

Wet suit
Just upgrade my normal scuba 3mm wetsuit to the Australian made frog skis 0.5mm wetsuit. This is a 2pieces with hood looks very similar to a free diving wetsuit. Definitely more streamline than my old scuba diving wetsuit

Mask
Just upgraded to free diving mask

Regulator
Have been using normal scuba regulator with Octopus but use small pressure gauge hooded to the D-ring. With upgrade this to the streamline hose configuration next year and use necklace backup secondary. May use transmitter type integrated air dive computer in the future to eliminate the pressure gauge.

Other stuff
Will reduce as much as possible to streamline

Your input on diving fins and my BP/W selection will be very much appreciated.

Thanks

 

[REVAN]

Your input on diving fins and my BP/W selection will be very much appreciated.

I think the best functioning long-blades have a soft tip (i.e. - a lot of fin taper for the stiffer fins). IMO - Soft, medium and hard fins should all have the same soft floppy fin tip, but few manufacturers actually make them that way, especially in plastic blades. I make my own stuff, and I'm not all that familiar with what is available out there from other manufacturers. Maybe someone else will write in with suggestions. The blade design is more important than the material. Personally, I think a well designed fiberglass blade is better than a carbon blade. My suggestion, stick to FG or plastic.

The only monofin I could recommend for use with SCUBA is one of my DOL-Fins. I use it and like it. Most divers are satisfied with the performance they can get from long-blade freedive fins and they like the versatility and being able to kinda walk in them.

FYI - I'm still building and experimenting, but I'm really just doing this for myself. I'm not planning to commercialize the scuba equipment, as there doesn't seem to be a market for it beyond myself and maybe a few other divers in the entire world. But, for the record, I'm using a DOL-Fin monofin and a new streamlined scuba kit. I'm probably getting cruise speeds in the 2.5 to 3 knot range and sprint speeds probably in the 4 to 5 knot range. It's a bit of a guestimation at this point as I haven't tried to measure the speeds yet. I'm still in the, 'working out the bugs' phase. It's finally getting pretty good, but I made some kit changes today based on last week's initial OW tests. I plan to go back to the ocean again in about a week.

On the back plate:

Again, I make all my own equipment, so I'm not the best guy to ask about commercially available stuff. However, the Freedom Plate looks really nice, and I think the guy that used to make them may be finally making them again. I think his name is Eric Sedletzky. But, as far as I'm concerned, a cheap $50 plastic back-plate of the old-school design is as almost as good as anything out there. Sometimes you can find old metal back-plates at garage sales / estate sales. I've got a couple old Daycor back plates in the closet here that I got that way.

 

[andy2667]

I think the best functioning long-blades have a soft tip (i.e. - a lot of fin taper for the stiffer fins). IMO - Soft, medium and hard fins should all have the same soft floppy fin tip, but few manufacturers actually make them that way, especially in plastic blades. I make my own stuff, and I'm not all that familiar with what is available out there from other manufacturers. Maybe someone else will write in with suggestions. The blade design is more important than the material. Personally, I think a well designed fiberglass blade is better than a carbon blade. My suggestion, stick to FG or plastic.

The only monofin I could recommend for use with SCUBA is one of my DOL-Fins. I use it and like it. Most divers are satisfied with the performance they can get from long-blade freedive fins and they like the versatility and being able to kinda walk in them.

FYI - I'm still building and experimenting, but I'm really just doing this for myself. I'm not planning to commercialize the scuba equipment, as there doesn't seem to be a market for it beyond myself and maybe a few other divers in the entire world. But, for the record, I'm using a DOL-Fin monofin and a new streamlined scuba kit. I'm probably getting cruise speeds in the 2.5 to 3 knot range and sprint speeds probably in the 4 to 5 knot range. It's a bit of a guestimation at this point as I haven't tried to measure the speeds yet. I'm still in the, 'working out the bugs' phase. It's finally getting pretty good, but I made some kit changes today based on last week's initial OW tests. I plan to go back to the ocean again in about a week.

On the back plate:

Again, I make all my own equipment, so I'm not the best guy to ask about commercially available stuff. However, the Freedom Plate looks really nice, and I think the guy that used to make them may be finally making them again. I think his name is Eric Sedletzky. But, as far as I'm concerned, a cheap $50 plastic back-plate of the old-school design is as almost as good as anything out there. Sometimes you can find old metal back-plates at garage sales / estate sales. I've got a couple old Daycor back plates in the closet here that I got that way.

Hi Ron,

Thanks for your reply. Just read from other thread of the deepblue form about your SR1 bi fins. It make perfect sense of adopting bicycle shoes as foot pockets in terms of comfort, fit and power transfer.

Interested in getting a pair if it has been tested to be durable and reliable. Are they available for sale yet?