Has anyone here ever made or used an Aqueon? | DeeperBlue.com Forums
  Guest viewing is limited
  • Welcome to the DeeperBlue.com Forums, the largest online community dedicated to Freediving, Scuba Diving and Spearfishing. To gain full access to the DeeperBlue.com Forums you must register for a free account. As a registered member you will be able to:

    • Join over 44,280+ fellow diving enthusiasts from around the world on this forum
    • Participate in and browse from over 516,210+ posts.
    • Communicate privately with other divers from around the world.
    • Post your own photos or view from 7,441+ user submitted images.
    • All this and much more...

    You can gain access to all this absolutely free when you register for an account, so sign up today!

Has anyone here ever made or used an Aqueon?

Thread Status: Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.

WTTriggerfish

New Member
Apr 10, 2009
8
1
0
Hi guys, I've been interested in the Aqueon / Powerswim type of swim aid for a while now, and since they don't look all that complicated I want to try to hack one together. Has anybody else done this, and if so do you have any tips? The patent for the aqueon shows symmetrical hydrofoils for the fins with a nice curve to them, and that being the part of the project I'd be least familiar with I'm curious if the device should work with flat foils instead. Seems like that should be a lot easier to build since I could just cut them out of marine plywood and throw a few coats of epoxy on. I seem to remember reading somewhere that even a flat wing produces lift somehow, so I feel like it will be okay, maybe just not as efficient as a more streamlined form. If it won't work, does anyone have any suggestions about how to go about making a decent hydrofoil with basic household tools?
 

trux

~~~~~
Dec 9, 2005
6,522
764
268
Yes, I have an Aqueon too. And yes, flat blades would work too, and in fact with a thin blade you could achieve lesser hydrodynamical drag than with Aqueon. Aqueon is not very good from the point of view - there is very little glide with it. You could also use sheets of fiberglass or carbon (like at Powerswim) - that would allow a thinner profile and a lighter construction than with Aqueon (the huge weight is another disatvantage of Aqueon). Also, when constructing a hydrofoil based fin similar to Aqueon, I'd advise against the spring system it uses - it is counterproductive: with increasing power it allows bigger angle of attack, while it ashould be rather the opposite. At a hydrofoil, the higher speed, the lower angle of attack you need. So you could either add angle delimiters, not allowing too high and innefficient angle of attack, or a self-sustaining hydrofoil (the pivoting axis shifted a bit more back).

You could also buy moulded carbon laminate hydrofoils - there are several manufacturers who offer them. Check out for example this one: Fastacraft - Carbon Fibre Products

You can perhaps find some more manufacturers for example here too: International Hydrofoil Society
 

efattah

Well-Known Member
Mar 2, 2001
3,294
487
173
I have used Tom's Aqueon, I did not like it. It is nowhere near the DOL-Fin devices in performance. Tom has dove 50m with it.

Also it is completely unmaneuverable.
 

WTTriggerfish

New Member
Apr 10, 2009
8
1
0
Thanks a lot guys, this has been very helpful so far. I did a little more research last night and as it turns out NASA has an airfoil simulator intended for college students on its site, and it's capable of simulating different fin profiles in water... looks like flow over a flat airfoil will stall at 10 degree AoA in water when moving at about 6 mph, which is what the aqueon people claim the average swimmer will get out of the device right? I was thinking I might do as Trux suggested and put some sort of tabs on the main shaft to keep the foils from rotating more than ten degrees up or down. I suppose the other option is to try something like a Dol-Fin, judging by the patent the original designer's thought was that it'd be better to have thrust nearer the center of a diver's mass, and our delphine and piscine friends seem to disagree so perhaps I do as well. I wonder though if the idea of attaching to the shins rather than the feet has something going for it; I know I can push a lot more weight at the gym on a machine than I can with free weights because the muscles in use are isolated and I wonder if that attachment method is more efficient because it spares the calf muscles?

Thanks again, links are great! I'm hoping to put some of the stuff together as the winter continues and if anything worth taking a photo of happens I'll see that it comes up. Any further advice is more than welcome!
 

Bill

Baron of Breathold
Oct 17, 2001
1,805
332
188
81
'I'd advise against the spring system it uses - it is counterproductive: with increasing power it allows bigger angle of attack, while it ashould be rather the opposite. '
Was this a misstatement Ivan? I'm having trouble with the concept. Without the spring, the angle of attack of a symmetrical foil will be about zero. Increasing the power decreases the angle of attack.
The coil's force increases slightly with more power because the spring is almost fully extended but the feathering force (trying to zero the angle) increases directly with speed plus the increased drag forces acting on the surfaces and the trailing edge.
It is a beautiful design and very simple with only one real fault. Like any optimized foil, it works best at one power setting. IMHO
 

trux

~~~~~
Dec 9, 2005
6,522
764
268
Was this a misstatement Ivan? I'm having trouble with the concept. ...
No, no misstatement. The angle of attack should be controlled by the forward velocity, not by the power input as it is at Aqueon. Additionally, the blade should flip to the optimal angle of attack instantly (just like at the DOl-fin), not being kept in the zero angle position by the spring at low power input.

Yes, the forward velocity reduces the angle of attack (which is wanted), but only insufficiently. The hydrofoil is not self-sustained - the pivoting axis is too close to the front of the blade. As you tell, it works well only when the power input is optimal (not too big, and not too low). You can easily overpower or underpower it, both resulting in much lesser than optimal efficiency. DOL-fin seems to be better also from this point of view.
 

WTTriggerfish

New Member
Apr 10, 2009
8
1
0
So if I do build this thing it'd be worth trying it without the spring? The reasoning makes sense but you'd think someone would have found that out by accident using one over the years. ...unless somebody did and that's why the Dol-Fin doesn't have one I guess. Heh, it'd be cool if somebody made a fin with a knotmeter and some servos that could adjust the maximum length of travel based on your speed.
 

trux

~~~~~
Dec 9, 2005
6,522
764
268
So if I do build this thing it'd be worth trying it without the spring?
It won't work, since you need delimiters of the angle of attack. And the best would be delimiters decreasing with the speed. You need the maximal angle of attack when accelerating from stand (close to 45 deg.), and very small angle at high cruising speed. It could be achieved by moving the axis of rotation of the hydrofoil a little more backwards, or by somehow controling the angle delimiters with the speed. If you keep the axis of rotation completely front, and use fix angle of rotation, you will either have great efficiency problems at slow speed, when starting accelerating (too small angle, hence moving too much water vertically), or low efficiency at cruising speed (too high angle, hence the blade cutting through the water with very little propulsion, and a high active drag). From this point of view, keeping the spring at Aqueon is certainly much better, than removing it without any modification.
 
Last edited:

Bill

Baron of Breathold
Oct 17, 2001
1,805
332
188
81
I now understand what confused me. You seem to define angle of attack as blade position compared to direction of travel while I use blade angle to direction of water flow. As you start moving (from a stop) my angle of attack is very close to zero and yours almost 90 degrees. Is that right?
Let me think about this.
 

trux

~~~~~
Dec 9, 2005
6,522
764
268
Yes, Bill, when I speak about the angle of attack I indeed mean the angle between the hydrofoil blade and the desired motion vector (forwards). Sorry if I was not clear.
 

REVAN

The Right Stuff
Mar 19, 2009
812
360
118
Hi guys, I've been interested in the Aqueon / Powerswim type of swim aid for a while now, and since they don't look all that complicated I want to try to hack one together.

WTTriggerfish - Just wondering if you ever tried to build anything. If so, let us know how it turned out. What problems did you have? How did it work?
 

jcapoot

New Member
Jan 15, 2021
1
0
1
66
I just saw this thread from 2011 while I was looking for something else. I have an Aqueon that I just posted on Craigslist in San Diego. I've had it since the 80's and never used it. Time to find it a new home!
John
IMG_3371.jpeg
 
DeeperBlue.com - The Worlds Largest Community Dedicated To Freediving, Scuba Diving and Spearfishing

ABOUT US

ISSN 1469-865X | Copyright © 1996 - 2021 deeperblue.net limited.

DeeperBlue.com is the World's Largest Community dedicated to Freediving, Scuba Diving, Spearfishing and Diving Travel.

We've been dedicated to bringing you the freshest news, features and discussions from around the underwater world since 1996.

ADVERT