Monofin Purchase advice

[PoseidonSv]

Excellent feedback of what info you gave, but was there some misunderstanding between 1,5 and 5mm socks?

I think I read he made it for 5mm and it works great with 5mm and well with 3mm?

 

[Fondueset]

My first fin was made for 5 mil socks - I prefer to use it with 3 mil.
My second fin is made for bare feet - I no longer put socks INSIDE my fins - instead I cut the toes out and put them OVER the fin. I do this with both my Tropol and my newest Starfins and my feet stay quite warm.

 

[Kars]

Hi Andreas,

Thanks for the email, very thoughtful.

I'm and happy with the remark that the fin-test is actually a combination test of fin and tester.
Also the remark that the circumstances are of a big influence is very valid. In a review of the fin I for sure would try to give mine impression of the following factors:

- Time to learn the fin optimal technique.
- Difficulty of performing the fin optimal technique.
- Difficulty of use in vertical, horizontal, turning and putting on.
- Time of comfortable use.
- Maximum speed over 50m.
- The practical lowest speed.
- The fin - human optimal efficiency speed.

Also I would like to collect the exhaled air after a 100m and 200m air, and analyse the remaining O2%. This number will be influenced by a great number of factors, but I'll still would like to explore How we can have these stabilised reducing the influences of the non fin related factors.
Yes I think we could also have the diver swim with a small air bottle and see how many laps he could do on 1 tank.

The subjective factors of liking the manufacturer and or the fin design need to be overcome as well.
Sure the designers need to take into account the abilities of their potential customers. And that will be reflected in the subjective numbers the fin tester/reviewer will give in the factors mentioned above.

A good profile video of the fins in use will demonstrate the abilities of reviewes to handle the fin exposing his (in)abilities. Perhaps add "initial impression and expectation" to the review.
A good side shot and rear shot of the reviewer swimming 100m will show the fin-human system and will reveal many of it's strong and weak points to the knowledgeable critical viewer. The reviewer should point out his (in)abilities, so people can differentiate between the human en fin.

Thanks again for your reply, maybe a monofin reviewer will pick it up. No at this time I do not find myself competent enough with a monofin to be a monofin reviewer, though I do have clear preferences and experience funded opinions.

Kars

 

[Mullins]

I'm inclined to think that you could get a better reading with O2 measurements, but you would have to get a measurement in both the blood and in the lungs before and after the dive.

I think you could probably get away with simply setting benchmarks for comparison (nofins, duck fins, bifins, different monofins) and measuring exhaled 02. Sure, it wouldn't be perfect. But if you could start by getting consistent results for each subject with the same equipment, pace and preparation then you could be fairly confident of seeing meaningful results when you change one of those variables.

Kars, I reckon you want to keep things really simple. Measure exhaled 02 for each subject for each fin at three different speeds (1m/s, 1.3m/s, 1.6m/s) over a single distance (say 150m).

 

[efattah]

I think a good way to measure fin efficiency is to do a 16x50m and record the final time, with different fins. Another metric is to swim 50m and wait underwater until the 1st contraction, and record the time, and take a 3 minute rest and repeat 10-15 times.

Of course you still need to know the best technique for each fin.

 

[Mullins]

Or just see how far you can go with each fin until you black out

 

[Fondueset]

Not pretending to meet any of these criteria I sprinted 25m in 9 sec easily yesterday - of course this is not perfect due to gliding the last 2 or 3m for fear of hitting the wall - I would not say full out - but close. Probably overpowering it a bit - I would guess, all things considered, the real pace would be 7 or 8 seconds but I don't sprint much. I can swim - full lungs and no weight - quite slowly with continuous undulations - 30 - 40 sec for 25m - perhaps a bit slower but it feels a awkward (up and down movement due to minimal activation of the blade). At 90 sec I can repeat 75m laps indefinitely with 55 seconds between. Probably around 1'18 per 75 is a smoother but still economical and I would say this is close to the speed/energy trade off point for this distance and interval for me. At an 18-20 second per 25 pace I can maintain with <= 10 secs between for quite awhile.

This with my Starfins, which is the easiest fin I've used other than my first Triton - which was comparable in stiffness. My Tropol is closer to being a sprint/depth fin in terms of stiffness.

Of course I'm just goofing around. Plus 18-year-old girls have diving practice in the next lane; which hurts my neck.

 

[esom]

about "human-fin system" testing:

what is needed for getting a rough overview about the relation of "energy used to move while wearing a special kind of fin(s)" and and a propulsion/drag index -in average* (maybe for a few different velocities) is someone doing a good meta analysis of reports of quite a few people. those people would have to dedicate a good time (in a double sense) into learning to swim efficiently with at least two different fins.

actually a thread about "the properties of fins observed by swimmers"**
can have the character of a report-analysis mix.

of course more "controlled testing" could be done, but the outcome would be more uncovered info about athlete and investigator than about properties of different fins. (interestingly as freedivers/ coach as well as scientists)


*or what is your idea of this, kars? in the end to be able to speak about fins, right?
**this observation is needed, otherwise the "real observer" called investigator has nothing to observe which can be believed to be efficient swimming... kars mentioned the unity of swimmer and fin

 

[Fondueset]

You could probably mostly accomplish the above by doing searches on most of the major brands and reading the threads. Consolidating that would be helpful and perhaps shave off some of the learning process for new find buyers.

If it helps here is my fin geneology

Waterway Nemo (soft)
Waterway Nemo (hard)
(never could tell a diff)
Got some help from Pete Scott and finally developed good undulation So
Triton Hyperfin (Soft 24 deg blade)
Triton Hyperfin (medium brutal footpockets)
Tropol Hyperfin (medium hard way comfortable 19 degrees)
Starfins (medium soft - shallow blade angle maybe 15-18)
Starfins (as above - 28-30 blade angle)

Maybe all of us who feel we have decent technique and have tried a lot of fins should make a list and rate what we've used according to a list of subjective and objective qualities.

For the first I suggest:

Build/workmanship
Materials
Blade Angle
Price
Delivery

 

[esom]

Hi Fondueset,

my post was more of a reply to kars' idea of summing up info about very different finstyle. -also bi-fins and stuff. for the rest i agree completly simply share experience as its done already here on deeperblue.

best Andy