Ankle weights

[stuartv]

Seems to me that weight is weight, whether it's in the mass of the fins, or worn comfortably around the ankle (so long as the ankle weights aren't 2lbs and up, where I agree that a different solution should be found)

A fin that is more dense, so it's more negatively buoyant does not necessarily have more mass in it.

I use Hollis F1 fins, which are a common recommendation for people with floaty feet. They are size XL and I weighed them recently using a luggage scale and with the fins hanging down into a pool. They were 2# negative. And they do cure my floaty feet.

But, I don't know if they actually physically weigh more than my Atomic Blade fins, which are spec'ed to be neutral (I haven't weighed them in water).

If the Hollis fins are no more heavy (i.e. have no more mass), but are more negative, then that is exactly why they are better than using ankle weights.

I guess now, I should weigh both pairs of fins, to compare. When I have time....

 

[geomatt21]

Thanks for the accurate response. To clarify, let's assume the diver's options are changing to a fin that is exactly 1lb more negative each, or keeping his original fins and wearing 1lb ankle weights. For simplicity sake, the 2 fins in question are identical in shape, design, and drag.. one just happens to be 1 lb lighter.

Btw with 2xLP85 Fabers, a 6lb V-weight, 5 lb tail weight, DUI suit with RockBoots, I wear ScubaPro Jetfins size XXL with spring straps. I also have the Hollis F1 size XL... are there are more negative fins on the market? I still share the floaty feet issue... It is not my rig, it is the shape of my legs... not sure how it's possible at 5'11" 180lbs. Oh, and I am not overweighted. I have tweaked my rig 6 times in the last month (different wing style, backplate location/type, drysuit, fins, weight location and type, etc) and NOTHING has fixed the feeling of my head down, feet being pulled up.

After exhausting every possible option, is there still never an exception to the "rule" of no ankle weights for advanced tech/cave diving? not even 0.5lbs under my drysuit?

 

[stuartv]

Thanks for the accurate response. To clarify, let's assume the diver's options are changing to a fin that is exactly 1lb more negative each, or keeping his original fins and wearing 1lb ankle weights. For simplicity sake, the 2 fins in question are identical in shape, design, and drag.. one just happens to be 1 lb lighter.

Btw with 2xLP85 Fabers, a 6lb V-weight, 5 lb tail weight, DUI suit with RockBoots, I wear ScubaPro Jetfins size XXL with spring straps. I also have the Hollis F1 size XL... are there are more negative fins on the market? I still share the floaty feet issue... It is not my rig, it is the shape of my legs... not sure how it's possible at 5'11" 180lbs

My point was (and is) that you seem to be equating heavier with more negative and that isn't necessarily the case. Two fins could be exactly the same weight and still have one that is 1lb more negative than the other. Until you actually weigh them in and out of water, you really can't say that "there is no difference between using more negative fins and using ankle weights."

Also, as I said in an earlier post, it may be the shape of your wing, not your legs. I have (or have had) 4 doubles wings. 2 of the wings let me have good trim. 2 of them make me turn head down/feet up. All with an otherwise identical setup.

 

[geomatt21]

Thank you for pointing out my confusing language, honestly. What I have meant this whole time is more or less negative, not talking about weight out of the water. I also edited my last post to show that I have gone through these attempts at changing every aspect of my rig, one at a time and combining different options.

 

[stuartv]

Gotcha. But, your question was (as I understood it) "why does it matter if I use ankle weights instead of more negative fins?" And the answer is, ankle weights add mass, which takes more force (thus, oxygen) to move. More negative fins may or may not add any mass. If a fin is more negative with the same mass (thus, more dense), then it doesn't take any more force to kick that fin.

How many different wings have you tried? I have one donut and one horseshoe that work well for me. I have tried 2 other donuts that turned me head down. Thus, I conclude that horseshoe or donut is not the relevant factor. It's the actual shape of the air cell and where it distributes the lift. Maybe you just haven't tried the right wing yet.

All that said, there is some basic physics here. Your wing gives you lift. Weight added between the center of lift and your feet will help keep your feet down. Weight removed from the center of lift or higher will also help keep your feet down.

Are you using a SS BP? Have you tried an aluminum one? Have you tried removing the 6# V weight and adding 6# to your weight belt?

 

[geomatt21]

I do primarily use a SS BP, but have used an aluminum one with 4lbs more weight on a belt with some success. I have been able achieve horizontal trim by changing my wing or backplate but it is always at the cost of having my lower back and buttocks clinched tight the entire dive, causing cramps and spasms after 20-30 minutes of diving. No matter what I do, by putting all my weight at the bottom of the tanks or lower, this makes my pelvis the pivot point where I feel like it is being pulled down by the negative buoyant force of the weights, while my feet are being pulled up by the positive buoyant force of displacement. It is uncomfortable and unsustainable to clinch my lower back and buttocks and extend my feet as far back as possible to help decrease the amount of gas that migrates to them. I am left with the same conclusion as our OP: to be comfortable I need more weight below my knees, if it's 1lb ankle weights then I just have to deal with the increased effort and gas consumption required to carry them, and tremendously enjoy the relief it brings to my lower back and buttocks... Not for trying 6+ alternatives before reaching this conclusion.

 

[stuartv]

Have you tried gaiters, to reduced the amount of gas moving into your feet?

It does seem to me like some people are just built in such a way that they need some weight down there. But, your build that you described just doesn't sound unusual. To the point where it just seems like you really should be able to get your trim sorted out without having to use ankle weights.

Have you worked with any kind of tech instructor who looked at you to help you sort it out? With everything you described, I would personally be giving some consideration to finding a GUE instructor (or other tech instructor that I had reason to believe was really, really solid on working out trim issues - I'm not a GUE guy - they just have the reputation for being really good at that) and paying for a mentoring session, probably in a pool, to work out the trim problem.

Maybe you need different tanks? I have an easier time with trim using longer tanks (HP120) versus shorter tanks (HP100). Ankle weights are probably more practical than buying new tanks. But, if you tried longer tanks and found them to "cure" your trim, you would at least know that and could be on the lookout for an opportunity to do some trading for tanks that work better for you.

 

[geomatt21]

I discovered these challenges and came to this conclusion during my GUE Fundamentals class (a total of 50 doubles dives prior to GUE). My instructor was extremely helpful in many ways but was also adamant about solving the issue without ankle weights, offering all of the possible adjustments I have tried. I sampled 3 different wings and decided to stick with my DGX doubles wing over the Halcyon Evolve or OMS 45lb horseshoe wings. I use gaiters and it definitely helps me from losing control of my legs/feet, but doesn't solve the back muscle strain issue or floaty feet. HP 120's with 7.25" diameter are in my future and absolutely make ankle weights avoidable. In the water I love those thanks, I just don't want that much weight on land or have the need for that much gas at this point in my diving career... all my dives are 180' and shallower, and my surface consumption rate is about 0.6-0.8cfm max

 

[stuartv]

10-4. I'm sorry to have made you re-live all that!

Maybe you should look for a mobster to piss off. A free pair of cement shoes should cure your floaty feet problem. ;-)

 

[cipherbreak]

Heavier/less buoyant fins? Might be enough to solve the issue without having to use weights.

Edit: Just realized you have determined a need for 3 pounds. Perhaps hit DSS for some bespoke SS fins.