Fins and manoeuvrability

[lowviz]

... This would be poor with a steel 100 or 120, due to negative charicteristics of the tank...

Easy.

weigh your rig underwater with a fish scale. For water, a pint is a pound. For your purpose, get a length of 1 to 2" PVC tubing from Home Depot, two end caps, and a can of glue. Cheap. Figure out how much internal volume you need to get everything neutral. Glue on one end cap fill with water until you get the number you need, that sets the length. Add a pound or two in length to compensate for the weight of PVC underwater or calculate it using its density. Pour water out, cut to length, dry, glue on second end cap. There is your streamlined float.

Here is how I zero the rig I use for determining wing characteristics, just an example of getting something really heavy to be neutral underwater.

Best part, nothing will change with depth, it is all rigid. Get it neutral and it will stay that way anywhere underwater.

 

[stuartv]

I've been following this thread. Y'all have got me really thinking about trying some freedive fins.

Looking at the Mako fins, the fixed blade ones are $68 and the replaceable blades ones are $90. The fixed blades are thermoplastic where the replaceable blades are a fiberglass blend blade.

Dan (or anyone else), have any thoughts on these? It seems like $22 extra is well worth it, if the competition fins are better - even if it's just a very small difference. As a concept, I like the idea that if I find I really like them, I would have the option to replace the blades later, whether it's to "upgrade" or simply replace worn ones.

And you say these fins would still work well for frog kicks and back kicks (in open water)?

 

[lowviz]

... And you say these fins would still work well for frog kicks and back kicks (in open water)?

I'll pay $68 to find out.

After using them, I'll decide what level to upgrade to. I like the idea that the $68 fins are one piece. I plan to throw them in the back with all my other dive stuff.

 

[REVAN]

After I got neck deep in this thread I reviewed some of the older material and it does seem like some of the same players are "emotionally all in" on certain brands. I really would like to demo a lot of these different fins but I am not going to fly to Florida to do it. for that cost I could just buy all of the fins in question.

gkrane; I'm near Tucson. I don't have anywhere near the fin selection that Dan has, but I'm in your state and I have a few cool toys including some nice composite blade diving fins. I have a 20m long x 12ft deep pool I use for evaluating dive equipment. Let me know if you want to come by and try some fins. It's probably best to use the contact information through my website Smith Aerospace - Home if you want to reach me. I don't seem to get email notifications from scubaboard, so if you PM me, I may never find out about it.

 

[danvolker]

I've been following this thread. Y'all have got me really thinking about trying some freedive fins.

Looking at the Mako fins, the fixed blade ones are $68 and the replaceable blades ones are $90. The fixed blades are thermoplastic where the replaceable blades are a fiberglass blend blade.

Dan (or anyone else), have any thoughts on these? It seems like $22 extra is well worth it, if the competition fins are better - even if it's just a very small difference. As a concept, I like the idea that if I find I really like them, I would have the option to replace the blades later, whether it's to "upgrade" or simply replace worn ones.

And you say these fins would still work well for frog kicks and back kicks (in open water)?

I think you would find that the fiberglass/composite blades are well worth the slight increase in cost. And with interchangeables, you may one day decide to have a soft blade for some conditions/durations, and a stiff blade for traditional dive duration days where conditions may be a bit "sportier"


Frog kicks expect perfection.
Helicopters also.
Reverse kick is possible, but the method you use is a bit different from how you do them with jets.
One of these days I will do a video on it.

 

[TN Traveler]

Please pardon a one post hijack, but:

Looking for suggestions/advice as to what ~18# wing pairs well with a wetsuit, Freedom Plate, and Mako's fixed-blade freedive fins?

Oxy 18# on a Freedom Plate is a dream.

 

[gkrane]

gkrane; I'm near Tucson. I don't have anywhere near the fin selection that Dan has, but I'm in your state and I have a few cool toys including some nice composite blade diving fins. I have a 20m long x 12ft deep pool I use for evaluating dive equipment. Let me know if you want to come by and try some fins. It's probably best to use the contact information through my website Smith Aerospace - Home if you want to reach me. I don't seem to get email notifications from scubaboard, so if you PM me, I may never find out about it.

I would like to take you up on that Revan but I am going to be heading down to South Texas on Nov 3rd for quite some time. Hopefully I will be able to get in quite a bit of warm water gulf diving.

 

[lowviz]

Dan,

A thought, make a "T" out of PVC pipe, a "Tee", and three end caps. That way you have both a handle and your needed buoyancy.

 

[dmaziuk]

If I remember correctly, these testers were mostly between 30 and 100 dives in their lifetimes....that makes them rank novices.

You are not the target demo for volume new fin purchases, we rank novices are. If I were a manufacturer sponsoring the test, that's exactly the kind of testers I'd ask for. Preferably with the beginnings of arthritis in the knee and ankle, too, as the average diving age seems to be right where that happens.

 

[danvolker]

You are not the target demo for volume new fin purchases, we rank novices are. If I were a manufacturer sponsoring the test, that's exactly the kind of testers I'd ask for. Preferably with the beginnings of arthritis in the knee and ankle, too, as the average diving age seems to be right where that happens.

I agree that I am nothing like the target demo for the high volume new fin purchases...but testing is another matter.

You can't employ testers that can't kick properly--and dont have any sense of what's good and bad in a fin. All they really know is whether their own defective kick style works with a given fin, or not. What you are missing, is that if you had ten of these rank novices, there could easily be 10 different types of defective kick shapes.

What if a rank novice, as in the video below, says that the Cressi Master Frog is a terrible fin, because he can't get it to push him around anywhere....and then you listen to him and get the split fins he likes, because they allow him to swim in this defective way----BUT--You, even though a new diver, automatically began your fin swimming from day one with a fairly reasonable kick shape, and had you tried the Master Frogs, you would have been pushed around easily and like a rocket by them, whereas the splits the tester endorsed so highly, gave you little precision and much less speed when you wanted it....but mostly just less precision and no frog kicking.
Point being, if you had it the way you suggest in your last post, you could only hope for a novice with the same kick shape and power that you have.....but you might only have a one in ten chance of ever getting that from a novice doing the testing.
[video=youtube;2VEthluthE4]https://www.youtube.com/watch?v=2VEthluthE4&[/video]

( would you want this guy to be chosen to test fins for you and the world?)

A better plan, would be to have only testers that understand exactly the right kick shape each fin requires....and then if you are a novice that buys a fin they say good things about, you know it is possible you may need an instructor or mentor( free for a mentor) to show you the right kick stroke, and help you attain it in the next 2 or three pool or ocean dives.