The Great 'Ankle-weights Debate'.

[scuba g]

Originally Posted by Al_Star

Ankle weights tend to be used by people who feel they have buoyant feet - because they are running their buoyancy on a drysuit. The clue is in the name - you should run your buoyancy on your BCD and keep yourself dry with your drysuit. Running with enough gas in your suit to prevent squeeze means no floaty feet sensation and means divers can actually acheive horizontal trim in a drysuit. This means they don't kick up the silt when diving.
The clue was also in my previous post "and as I was sidemounting and using my suit for bouyancy", I wasnt using a BCD but my drysuit only.
As for the weight on the feet making no difference to effort, well of course it does.
As mentioned, heavier fins or light fins with ankle weights, I said very little difference, not "No" difference, that would throw physics out the window in this case.
If I want to work on fitness at the gym then I add more weight and more resistance to the exercise. It doesn't take a sports scientist to tell you that ankle weights make your finning more of an effort and therefore make you work harder on a dive and use more gas.
Thanks for lesson in weight training, Im not wearing a dumbell on my ankle but a small amount of lead, If I was using that much energy were I was using more gas I would stopped using them, yet again they are just enough in weight to add some negative trim which with my neoprene is what I like.

Decent fins can help such as jetfin style fins - they are negative so you get a bit of a counterbalance. The extra weight which adds more a little more effort to your finning is easily offset by the fact they let you swim more efficiently.
See what I said above, I wear Mares Quattros and they are fairly light, and I find my finning is not affected while wearing ankle weights, we walk around carrying alot more day to day, so by finning correctly its causes very little difference, we are not wearing 5 or 6lb weights here.

Having actually swum for 9000 feet in one of my last cave dives there was no way I could have managed it with blocks of lead around my ankles and my old Mares quattro's!
Wearing blocks of lead wouldnt be very clever, a pair of 1lb or 1.5lb weights divided between each ankle doesnt have any "tiring affect", Ive never finished a dive and felt my legs are tired from ankle weights, if I did I would have binned them along time ago.

As with all divers and their techniques, there will be differences which will be agrued and discussed and never put to rest, I have worn them for years and feel with my experience and amount of dives that I am happy with them, but as I said, if others dont want to then so be it.

Cheers
Al

Im off to see what else Im doing wrong!

[Adrian Kelland]

Originally Posted by Diving Dude

First option should be to use the search feature.

You really don't expect people to actually use that do you?

[John63]

Originally Posted by Clare Gledhill

Don't confuse weight with propulsion. Most people wear ankle weights as they believe that they cannot achieve stability without them - not for propulsion.

Hi Clare,

thanks for the reply. I wasn't confusing propulsion and weight, but was assuming for the sake of discussion that both fin types would have the same -ish propulsion to remove a variable from the equation.

This gets the question back to

"whats the difference between a heavy fin and a light fin + small ankle weights"

which was tageted at those who indicated that ankle weights would increase leg/muscle strain or increase effort. Clearly whether the weight is on the ankle, or attached to the foot in the shape of a fin, the additional effort required due to the increased weight would be broadly similar.

The answer would therefore seem to be that there is no real difference (in terms of effort) but a little bit less kit to take along and maybe less of a snag risk, both of which would be beneficial.


The difference in moment arm as has been mentioned in another post would be insignificant, especially if the diver is in a knees bent DIR style trim position as shown in the thumbnail below (copied from your website - I hope this is okay as I had trouble creating a link).

Originally Posted by Clare Gledhill

Jet fins are slightly heavy - and do act as a marginal counter weight at the end of your leg (300 grammes or so in water) - but reasonable trim can be achieved in the flimsest of fins - or indeed without any at all.

No argument here, but if somebody does have a problem with trim (for whatever reason) and if they feel happier and more comfortable with weights, is it really such a big deal? Surely the minimal increased risk of a snag is more than offset by their more relaxed state in the water; less stress, better air consumption etc

Originally Posted by Clare Gledhill

I'm constantly told of people who find that their latest 'all singing all danicng' fin which costs god knows how many hundreds of pounds is faster than a jetfin. Well it may be in a straight line over a very short distance. But as Al says, swim for any distance in a cave, especially with flow, and you learn that a jetfin does the trick for propulsion and manouverability. That's why most US cave divers who have to swim distance in flow conditions wear them - not just DIR divers.

Haven't dived in flowing caves, or any caves for that matter, so I can't comment, but I can see that a shorter fin might be advantageous in some of the more confined areas.

In open water I normally try to avoid swimming against a strong current whenever possible. I have done a number of 2hr dives (not in jets) and have not had a problem. Done the same in jets and don't have a problem in those either.

Originally Posted by Clare Gledhill

Jetfins - cheap, reliable, just a p.i.t.a. for your luggage allowance

Not as bad as the ankle weights though

I'm really not pro / anti ankle weights at all and feel that there's not a big argument either way. Horses for courses I guess.

offtrack slightly from weights to fins. For what it's worth, my first ever fins (way back in late 1970's) were jetfins. Sadly, my feet have grown a little since then but they are still in the back of the cupboard somewhere. I really must have a tidyout.

Cheers, John

[scuba g]

Originally Posted by Clare Gledhill

Don't confuse weight with propulsion. Most people wear ankle weights as they believe that they cannot achieve stability without them - not for propulsion.

Sorry Clare, I dont get this comment, propulsion is to do with force (as Id say you are well aware ) and weight is well "mass", the stability needed for good trim depends on the suit, I find a neoprene neing naturally more bouyant, in some cases IMO, benefits from the diver wearing a small amount of weight on the ankle, in a membrane you are less likely to wear them.

[Fiona]

Originally Posted by Diving Dude

First option should be to use the search feature.

Originally Posted by Adrian Kelland

You really don't expect people to actually use that do you?

Sorry they must have used the search function otherwise you find a very very old thread.

Far too few people even bother


......... and if anyone wants a pair of ankle weights I am sure I have two pairs in the garage, don't think I'll need them again

[CatB]

My drysuit actually has built in shot pockets around the ankles which has 2 advantages;

1) No chance that they will fall off or snag
2) No-one can see you have 'ankle weights' so I don't get told why I shouldn't need them

It works for me and means I can take a kg off my belt.

[Lou]

Originally Posted by Fiona

......... and if anyone wants a pair of ankle weights I am sure I have two pairs in the garage, don't think I'll need them again

Is that because you use big, heavy fins now?

[Fiona]

Originally Posted by Lou

Is that because you use big, heavy fins now?

Of course

Just wait until you see my new shiney twinset

[gpj]

I've just ditched my ankle weights (not literally) after fiddling and farting with my bouyancy for the past few years I decided to do the PPB course, (one thing I'd recommend everyone to do!) on my second dive my instructor suggested to leave them off, it made one hell of a difference (they were only 0.6kg each) but it made such a difference to my trim, I found that they always made me feet heavy, a bit of a pain stirring up silt near the bottom and without them it made hovering on the 5m safety stop an absolute breeze.

[Al_Star]

Originally Posted by John63

Hi Clare,

thanks for the reply. I wasn't confusing propulsion and weight, but was assuming for the sake of discussion that both fin types would have the same -ish propulsion to remove a variable from the equation.

This gets the question back to

"whats the difference between a heavy fin and a light fin + small ankle weights"

which was tageted at those who indicated that ankle weights would increase leg/muscle strain or increase effort. Clearly whether the weight is on the ankle, or attached to the foot in the shape of a fin, the additional effort required due to the increased weight would be broadly similar.

The simple answer is the fins don't weight anything like as much as a ankle weights. My ankle weights now help provide some weight in the nose of my scooter - so they do have a use, it's just not around your ankles!

I would say that some negative buoyancy in your fins can help you balance. So if you are have 300 gram ankle weights and neutral fins then there isn't a great deal of difference. However most people's ankle weights are two to three time that negative.

The negative buoyancy of jetfins is also offset by the efficiency of your fin strokes. Any time you can be more relaxed and efficient in the water you are working less hard, ongassing slower and using less gas. Unfortunately my mares quattros never found a new use and were not replaced when the dive boat I'd been using sank!

Cheers
Al