Scubapro XL Jets vs IDI/XS Scuba XL Power Fins

[*Floater*]

Well, I asked one of the people in charge at the gym about using the pool with scuba tanks and she called someone else and then left me a message saying that they couldn't allow it because it was "a real risk management issue." I'll try again to see if I can reason with them, but whoever is making the call probably knows nothing about scuba and just doesn't want to deal with this in case something happens.

Maybe I can convince them that the lifeguard on duty is fully capable of rescuing me if I stop moving on my lane - at least she will be after I lend her a pair of sheers and show her the BC inflator button, or maybe if the instructor for the OW course agrees to "manage the risk" they'll let me do my fin testing - I've rented gear and done a few dives through their operation so maybe they'll help me out.

Also, if this does work out then I'd love to test the OMS slipstreams as well (size XL most likely) if anyone would be willing to lend me a pair. I would do the test with independent doubles (AL80's most likely with H Evolve 40), same 1st and 2nd stages on both tanks, some excess weight to increase wing drag, and I would switch tanks along with the fins every 10 laps or so and record the exact times. I'm thinking 40-60 laps total at least. At the end of it I'd compare the amount of gas consumed from each tank and the total times. I would swim at the bottom of the pool the way I swim in caves when trying to cover as much distance as possible on that third (steady frog kicks with max glide, slow, controlled breathing).

 

[*Floater*]

Okay, I talked with the guy in charge of the pool and he said I could use the tanks in there if the scuba instructor assumed responsibility for me, so there's hope again, especially since I've dealt with the shop in question before - waiting for a reply from them now.

CompuDude, how did the XXL slipstreams work out for you? How large are their foot pockets compared to XL jet pockets?

 

[kidspot]

Thanks for the report Floater - Very informative.

I have never found a pair of boots I could wear with my XL jets, but on a dive boat a few weeks back I ended up borrowing a pair of XL Jets and boots they had on the boat and the fit was really nice ... I have considered buying another pair of XL Jets to see if I can't find a larger pair - They would fit SO much better than the XXL Jets. I still think ScubaPro just needs to make an inbetween size

Thanks again for your report.

Aloha, Tim

 

[*Floater*]

I still plan to test them further, and the OMS Slipstreams too. The orientation meeting for the scuba class at my university is this Monday, so I'll ask them there about using the pool - I prefer to ask in person because people are generally less likely to reject someone's request when face to face with the person. If they let me dive in the pool then I'll measure my air consumption and lap times on each set of fins while wearing doubles and finning the way I fin when trying to max penetration on a third. The actual class won't be until early October, so that's when I would do the testing if things work out.

 

[*Floater*]

Good news. I went to the scuba class orientation meeting today and the guy from the shop I had dove with in NJ was there to run it. He had no problem with my request so the test should go ahead the first Friday and Saturday of October.

I also bought a pair of OMS Slipstreams (XL) just to see if they are in fact better than the jets, though I will probably sell them off soon after I've done the test. My first impression is that they are about 50% lighter than the jets, the foot pocket is about the same height and width but maybe about half inch deeper, at least my foot goes in slightly deeper and they holds a greater volume of water.

The slipstream blades are also stiffer than my jets, so they work a tad different. You don't get as much flex and bounce back on frogkicks as with the jets and on my best laps I needed 10 kicks to dive the pool length whereas with the jets I need only 9 - but that may just be lack of experience with the particular fin, plus breath-hold swims are a little different than scuba swims anyway since you are running out of air. And the slipstreams are lighter which could theoretically result in less exertion, or it could work the other way around - lighter fin = less momentum for moving water? I guess we'll see when I get to do my test.

My plan is to test jets vs. slipstreams during the first pool session and jets vs. power fins the second session. If I have time and energy left then I might do some finning with the force fins too and see whether they actually are good for air consumption rate, though it would not be an objective test since I'm not used to them.

 

[*Floater*]

So took a few pics of the OMS slipstreams next to the Jets and measured them.

Jet foot pockets hold about 1100g of water (per pocket).
Slipstream pocket hold about 1200g of water. They are half inch deeper, otherwise exactly the same, I can put them against each other and they match exactly, same mold, except OMS fins have drainage holes.

The jets (with springs) weigh about 1440g per fin. Slipstreams (with rubber straps) weigh about 1040g per fin. So at most 30% lighter than jets. (Not half their weight as some people say).

As for performance that is still to be seen. The only thing I notice with both the Power fins and Slipstreams is that since they have stiffer blades I don't get the familiar whip lash or whip crack effect (for lack of a better term) I can generate with the jets. Take a look at this modified frogkick: http://www.divetekadventures.com/Videos/VideoModfog.htm

See how with slight ankle moves the jets bend against the water pressure and then lazily but fluidly snap back - not sure if that's good or bad from an efficiency point of view, but I like to feel it. I don't think I'm getting that with the other fins. With the frogs I got too much of it, they were too soft for my taste because the center panel of their blades is made of very thin rubber, besides they were a little too small for me.

 

[CompuDude]

Hey, Floater, I finally tried on my SlipStreams in the pool last night. Very interesting experience.

XXL SlipStreams seem to be sized between XL Jets and XXL Jets, from what I can tell. I was able to wear them over my size 10.5 Converse, and the spring straps held them on fine, although I could feel my foot rattling around inside a bit. I'm toying with going with Rock boots in a larger size, since the 10.5 Chucks are pretty tight on my feet as it is, or else I may sell off these XXLs and pick up some XLs. If they're truly a shade bigger than the Jets' foot pockets, they might fit my existing footwear perfectly.

Wearing them (in the pool) was interesting, though. They felt VERY light on my feet... a little less like swinging a heavy object through the water, and yet there was less feedback on the snap of the blades, as you observed. Plenty of power, though... possibly even a bit more than the Jets, which makes sense if they're a bit more rigid. All my kicks seemed to work pretty much identically to the Jets, though.

I look forward to traveling with these!

 

[*Floater*]

If they're truly a shade bigger than the Jets' foot pockets, they might fit my existing footwear perfectly.

They are a shade deeper (half inch). The width and height are about the same but the foot pocket material is smoother and more flexible. My size 11 Chucks go into both easily, the size 12's go into both too, but there's more resistance when I push them into the jets. Still, it's not a big difference so don't count on XL slipstreams fitting.

Are the XXL slipstream's foot pockets bigger or smaller than turtle foot pockets?

 

[*Floater*]

I wear size 10.5 Chucks with my DS but that's a really tight fit... probably a bit tighter than I should tolerate. Considering how tightly they fit into my XL Jets, however, I'm surprised you can get size 11's in.

By the way, is the problem that you have a hard time getting the XL jets on, or that they hurt your feet once on? How much of your 10.5 Chucks (bottom) stick out of the XL foot pocket?

If you can get them on but they are uncomfortable, then you might want to try loosing the straps. I keep mine fairly loose. Just tight enough that my feet don't feel sloppy inside the fins, which is to say just about touching since my feet fill the pockets quite well to begin with. Whenever I've had the straps too tight I always felt pain and discomfort when diving with the jets for a while. Same with the OMS fins until I loosened the rubber straps just to the right tension.

 

[Hoosier]

The jets (with springs) weigh about 1440g per fin. Slipstreams (with rubber straps) weigh about 1040g per fin. So at most 30% lighter than jets. (Not half their weight as some people say).

Wearing them (in the pool) was interesting, though. They felt VERY light on my feet... a little less like swinging a heavy object through the water,

Interesting.. The weight review wasn't a fair comparision. I guess it would be 15% difference after adding a spring straps on Slipstreams though. CompuDude felt very light...... Hmm~~~

I look forward to hearing more review. We don't have any OMS stock in my region..