A rig you can dolphin kick—ideas?

[covediver]

Cool link, thanks!

I think these kinds of systems are primarily used for public safety diving. they had a sport model at one time but I am not sure of the production status.

 

[dmaziuk]

With AL80 a bit lower than I can reach I can do dolphin kick w/o banging my head on the 1st stage just fine. Mind you, I don't put that much back into the kick b/c my back doesn't really bend right. I've always sucked at bat.

Edit: ah, yes, the rig: basic no-name backplate w/ a 25lb wing and a pair of Accels.

 

[REVAN]

When swimming gearless one of my favorite “resting” kicks is dolphin, and I was wondering if any of you folks that have experienced lots of different BC’s, back plates, sidemont, scooters, etc. have ever found a sweet dolphin rig you can really wriggle in?

I've done a lot of diving with the dolphin kick and have built several dive kits that are intended to exploit it. Mostly, my designs were focused around using my DOL-Fin monofin, but I have also experimented with bi-fins that I designed/optimized to exploit the dolphin kick. The bi-fins worked better than I had expected, though the monofin was still more powerful and efficient overall.

You may want to check out the videos on my youtube channel. Much of the more recent uploads have to do with scuba. going back in time, it will transition to mainly freediving.

smithaerospace

Some highlights from my channel to show the scuba evolution of things are below.




PS - The bifins were a sidestep because I figured that very few scuba divers would be interested in using a monofin to scuba dive even if it worked really well. In the end, I found very few scuba divers were interested in swimming efficiently at all. Most are happy with using low cost fins and moving at speeds in the 0.5 to 1.0 knot range or even slower. I've since moved on to other work and no longer professionally build dive gear for others.

 

[RainPilot]

I've done a lot of diving with the dolphin kick and have built several dive kits that are intended to exploit it. Mostly, my designs were focused around using my DOL-Fin monofin, but I have also experimented with bi-fins that I designed/optimized to exploit the dolphin kick. The bi-fins worked better than I had expected, though the monofin was still more powerful and efficient overall.

You may want to check out the videos on my youtube channel. Much of the more recent uploads have to do with scuba. going back in time, it will transition to mainly freediving.

smithaerospace

Some highlights from my channel to show the scuba evolution of things are below.




PS - The bifins were a sidestep because I figured that very few scuba divers would be interested in using a monofin to scuba dive even if it worked really well. In the end, I found very few scuba divers were interested in swimming efficiently at all. Most are happy with using low cost fins and moving at speeds in the 0.5 to 1.0 knot range or even slower. I've since moved on to other work and no longer professionally build dive gear for others.

I love these vids. I wish I had the mechanical nous to build stuff like this.

 

[dmaziuk]

I always wondered why not put a shroud/cage around the neck of the tank, like they do on propane tanks, and then you could mount it upside-down without smashing the 1st stage in process -- and have the hydrodynamic round tank butt in front and the knobs and hoses tucked out of the flow behind your butt. As a bonus: no problem reaching the knob down there.

If they haven't gone to this setup in all these years, there's gotta be a downside I'm not seeing.

Edit: collar, they call it, aka protective neck ring.

 

[REVAN]

I always wondered why not put a shroud/cage around the neck of the tank, like they do on propane tanks, and then you could mount it upside-down without smashing the 1st stage in process -- and have the hydrodynamic round tank butt in front and the knobs and hoses tucked out of the flow behind your butt. As a bonus: no problem reaching the knob down there.

If they haven't gone to this setup in all these years, there's gotta be a downside I'm not seeing.

Edit: collar, they call it, aka protective neck ring.

The collar on a propane tank is welded on. That's fine for a tank sitting at 100 psi. I think welding on a steel scuba tank would simply add too much uncertainty to the strength of the tank given the pressures they operate at and the tank's wall thickness. Making the tank's wall thicker isn't an option because the tank would turn into an anchor. Welding T6 aluminum will significantly weaken the metal, so a welded collar is not an option for aluminum tanks either. If you want a collar, it will have to be attached with some other method that won't weaken the tank.

 

[aquacat8]

REVAN Your stuff is just super cool, I’ve admired it for years!

 

[dmaziuk]

If you want a collar, it will have to be attached with some other method that won't weaken the tank.

Yeah, I suspected welding may be no good. Hose clamp method should work but you'll need to make sure it's tight enough the tank won't slide out when you lift it by the collar.

 

[undrwater]

I believe (if memory serves me correctly), @Akimbo inverted his tanks with a protective cage. This was doubles, so may not generalize to single tank.

I too, like @REVAN 's work. Maybe minimalism will have a resurgence someday.

 

[aquacat8]

REVAN Is that a custom freediving snorkle I see? How clever!