Benefit from Mono?

[penguinator]

I was reading up on monofins and was contemplating having a go...

But.. im not to sure if it will be suited to what I want out of freediving.

Im not to fussed about how far down I can go, I just want to maximise bottom time, whatever depth that may be.

Im not exactly a spearfisher (all though I would like to dabble in it later on), but I just like to frolick and explore underwater for the maximum amount of time.

I heard that monofins can get you there faster and get you deeper, but would they use up more oxygen?

[monofin_diva]

actually i have found that they are more efficient while swimming because your muscles aren't really using up as much oxygen as they would if you weren't using one. so that increases your bottom time.

it's just an efficient way to propel yourself underwater so a lot less energy is expended.

[efattah]

Proper use of a monofin will dramatically increase your bottom time at *any* depth. I have caught fish, spearing with a mono as well. Although for spearing I think a pole spear with a mono works best. A speargun with a mono is more difficult.

[monofin_diva]

Originally Posted by efattah

Proper use of a monofin will dramatically increase your bottom time at *any* depth. I have caught fish, spearing with a mono as well. Although for spearing I think a pole spear with a mono works best. A speargun with a mono is more difficult.

do you have more info as to why?

i would think.. at least from my own experience.. the efficiency of the fin uses less energy... which in turn uses less oxy.

is that true?

or just my observation..

i'd really like to believe that's true.. i know my dynamic apnea with mono is a bout 3 or maybe less than 3 min. not great but that's where i am (i'm workin on that). dynamic without great fin is like ... hmm. 2 maybe a bit less. i just glide under the water with it and i dont feel the urge to breathe nearly as much with my greatfin as i do without it.

but for me i can't swim without it.. LITERALLY..without my mono i swim like a drowning rat.

[jome]

IMO the biggest benefit from using a mono is that:
a) it helps you leave the surface more efficiently
b) it helps you leave the bottom more efficiently.

In terms of the "easy part" of a dive, where you are nearly neutrally buoyant, the difference is not as dramatic, but the difference in overcoming positive buoyancy as well as gravity at the bottom, those critical first 10-15 meters in leaving the surface and after turning, is huge. Monofins was originally designed for fast, powerful swimming and in those parts of the dive where you need the power, it helps tremendously.

That's just my opinnion

I would not consider a mono for spearfishing though, just because it is not as manouverable. Although even that could probably be mostly over come with training...But the biggest thing is that I cannot dive near the bottom without raising a huge clould of silt, which with bi-fins is easy to do with frog kicks

[monofin_diva]

Originally Posted by jome

IMO the biggest benefit from using a mono is that:
a) it helps you leave the surface more efficiently
b) it helps you leave the bottom more efficiently.

In terms of the "easy part" of a dive, where you are nearly neutrally buoyant, the difference is not as dramatic, but the difference in overcoming positive buoyancy as well as gravity at the bottom, those critical first 10-15 meters in leaving the surface and after turning, is huge. Monofins was originally designed for fast, powerful swimming and in those parts of the dive where you need the power, it helps tremendously.

That's just my opinnion

I would not consider a mono for spearfishing though, just because it is not as manouverable. Although even that could probably be mostly over come with training...But the biggest thing is that I cannot dive near the bottom without raising a huge clould of silt, which with bi-fins is easy to do with frog kicks

i can't swim with stereo fins so i don't have any input on that.. but i noticed when i ascend i'm glad i have a mono. it takes very little effort to get back up to the surface for that much needed first breath. i know a couple of people that DO use their mono for spearfishing with great results. personally, i'm more manouverable with it. i'm capable of the more quick stops and turns than i am without it.. then again i'm a crappy swimmer without my mono so i guess i've just learned to use it to my advantage. i've never picked up bi fins because it feels unnatural for me to swim with my legs apart.. and without the fins i have a mean doggy paddle or i just frog kick.

[octopus]

When bi-finning you create turbulence with four edges, as oposed to two in monofin. There is also a bit of unwanted interaction when one bi-fin passes the other. You would like as much as possible of your energy to be used for forward movement and as little as possible for creation of eddies. All things being equal, monofin is more energy efficient.
Have you ever seen a fish with two tail-fins?
Even mammals (with sufficient evolutionary time in the water) have reverted back to single tail fin.

[OceanMan]

I don't think monofin is more efficient than bi-fins. Monofin has more thrust, which is very different from efficiency.
In the end, the world's best performances in dynamic apnea are made with bi-fins (Tom Sietas 223m, Stephane Mifsud 213m). Monofins are not far away from that which probably mean that bi-fins and monofins have the same level of efficiency.
Just my opinion.

[efattah]

Originally Posted by OceanMan

I don't think monofin is more efficient than bi-fins. Monofin has more thrust, which is very different from efficiency.
In the end, the world's best performances in dynamic apnea are made with bi-fins (Tom Sietas 223m, Stephane Mifsud 213m). Monofins are not far away from that which probably mean that bi-fins and monofins have the same level of efficiency.
Just my opinion.

Dynamic apnea is not diving. In dynamic, you need only a small force to move forward. When fighting extreme buoyancy or negative buoyancy, a monofin is FAR more efficient. Try carrying a 50lb weight off the bottom with bifins, and try again with a mono.

[OceanMan]

Of course with high thrust requirements, monofins become more efficient. I think it's not true anymore when the level of thrust is the one of dynamic apnea.

I was answering Octopus's post where he talks about edges turbulences and other stuff that would make monofin more efficient than bi-fins in any condition which, I think, is not true.

[octopus]

I am comparing them purely as propeling devices, with respect to the energy losses. You'll always get more power into the forward motion out of single 2 kW motor then out of two 1 kW outboards positioned next to each other - due to turbulence losses.
The slower you work with your bi-fins, the less eddies you create and closer you get to the monofin efficiency (hence long straight fins for freediving and slow movements during record bi-fin dives). If you try to go really fast with your bi-fins, you'll start putting more and more energy into creating whirpools rather than into forward movement. As a thought experiment, just imagine increasing number of limbs and fins (guess why split fins are not used for freediving).
As I said, evolution always (eventually) gets to the optimal solution in efficiency department.

I'll repeat, I completely neglected human body in this argument.