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Author Topic: SP Jetfins sinking legs  (Read 3111 times)

mlchang

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SP Jetfins sinking legs
« on: 19 Dec 16, 17:48 »
Hello everyone,

I have recently purchased a brand new pair of SP Jetfins a few months ago.

Tried it out on the swimming pool several times and I had no problems in bending my knees upwards parallel to my body maintaining the horizontal trim position.

However, just 2 days ago while I was out diving with it, I realized that my feet was sinking thus not able to maintain the flat position while my leg upwards.

I was told that the fins are too heavy and to change to other types of fins. I am reluctant to change therefore are there any ways to counter such problems? Or if anyone is facing the same problem here?

Will shifting my weights from my weight belt to the tank strap going to improve my trim? Or changing to a positively buoyant booties (if any) help? I only wear rash guard and board shorts for dives. Or will changing to a wetsuit help to counter my sinking feet?

Thank you very much peeps.

DIN

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Re: SP Jetfins sinking legs
« Reply #1 on: 21 Dec 16, 21:08 »
I'm afraid there are no other ways around it. We human are not made the same. Some have floaty feet while others have sinking feet. If you fall in the latter category, the only way is to get rid of that rubber brick and get a lighter fins.

I doubt you will have any success with extra weight on your tank strap. The only solution is to dive more often and get use  to the fins. You just have to force yourself into trim position every time until its second nature. Good luck!  :D
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bighead

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Re: SP Jetfins sinking legs
« Reply #2 on: 22 Dec 16, 16:50 »
use float arms on ankles !! :D :D :D

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cloudberrie

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Re: SP Jetfins sinking legs
« Reply #3 on: 01 Jan 17, 02:00 »
I started with jets and loved it. Though it was heavy, after diving more and getting use to them, they were great. Powers there and great manuavabulity.

Lost the right jets and so had to get a new pair. Went with the Hollis F1s. Although they costed a bit more he the jets, I got lot more power per kick with them. And the foot pockets were huge! Cons it they were larger in size. Couple with their heavy dry weight, travelling with them was a pain. Plus being tt long, the fins have started to split on its vertical rails at the end of the foot pocket. Figure it might be because the fins are long and that's the part tt flexes the most.

Just gotten a pair of deep6gear eddy fins. Same more as the jet, but much much lighter, and with a foot pocket the size of the F1s.  Cost only USD75. Looking forward to trying them out during my next dive.
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orpheusdive

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Re: SP Jetfins sinking legs
« Reply #4 on: 10 Jan 17, 03:02 »
Looks like no one gave a proper solution for you.

Hope this picture helps




mlchang

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Re: SP Jetfins sinking legs
« Reply #5 on: 20 Jan 17, 15:58 »
Hi All,

Thanks for the replies.

Hi DIN,

Thanks. Yeah I have tried switching to the OMS Slipstreams fins and tried the below setup.

During the recent dive, I've actually borrowed my instructor's Alu Backplate Wing BCD, removed a weight from my belt and placed another one on the back of my tank. So i'm left with 2 weights on my waist and with the OMS Slips. The results are better than my previous ones where my legs just kept sinking forcing me into a vertical position. However, I don't think I'm still in trim as I still can feel my legs position below my waist line.

Hi orpheusdive,

Thanks for the illustration and help.

However, I'd like to know the below based from the picture provided;

1) How to you redistribute air to lower part of BCD?
2) The thicker the booties the more positively buoyant? If so, the size of the fins will be different am I right?
3) Neoprene Sring Straps, do you mean like below?



siaokao

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Re: SP Jetfins sinking legs
« Reply #6 on: 25 Jan 17, 17:05 »
Dear ML

Achieving flat trim is not just about switching fins and moving weights, they will have some effect for sure, but real stuff lies within yourself.  Assuming by shifting weights and wearing buoyant booties etc, you are able to achieve trim at 10m, how can you be sure you can do the same at 30m, considering your buoyant boots or wetsuit will lose buoyancy at 30m?

Key to good trim is first achieving good buoyancy control.  From my very limited experience (especially limited these days),you carrying 3 weights with an alu backplate setup sounds a little excessive.  Overweighting IMHO, creates many complications, stopping you from achieving good trim and freedom underwater.

A good way to fix this issue is not to spend more money on equipment but to sign up for a proper course.  A good course may sound expensive but it will save you plenty of experimental gear purchase, frustration and add to your dive safety and enjoyment.

For your information, I wear an XXL size jet fins with steel spring straps and stainless steel buckles.. I think my trim is ok. :)
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stupidawg

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Re: SP Jetfins sinking legs
« Reply #7 on: 25 Jan 17, 17:39 »
Personally I'm on XXL Jet Fins as well. Yes they are heavy but it has provided me the power and control . I am also able to back fin with it. As shown in Orpheusdive's picture, you can redistribute the air in the BC to the lower part. You can do this by shaking your BC. This was what I did too. And also with some practice, I have gotten used to them.

Cle

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Re: SP Jetfins sinking legs
« Reply #8 on: 28 Jan 17, 21:12 »
you can borrow instructor's gear
so you have an instructor.. if your instructor cannot teach you trim, maybe find a better instructor?
« Last Edit: 28 Jan 17, 21:14 by Cle »

mlchang

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Re: SP Jetfins sinking legs
« Reply #9 on: 01 Feb 17, 15:48 »
Hi siaokao,

Thanks for the input. Never knew gear could lose its buoyancy as you go deeper.
I did asked a couple of dive centers if they have any courses related on trim and buoyancy and they eventually asked me to pick from the PADI Specialty Courses offered.  :(
Anyway I appreciate your help and advise on this.

Hi stupidawg,

Thanks.

Hi Cle,

Yes I know where you're coming from. Majority of the instructors I've came across here does not really emphasize on proper trim, proper finning techniques and also buoyancy. Their mentality is as long as you are able to move and stay underwater, you are good to go.