What's the deal with drysuits and ankle weights?

[Paco II]

As indicated in other recent posts, I am a new drysuit diver (only 2 dives so far). On my first dive (part of DS cert), I was underweighted. I've since engaged a number of more experienced drysuit divers I know on topic of proper weighting and one thing that keeps coming up over and over is that I am told that I should use ankle weights. I've never used ankle weights as a wetsuit diver, and my preference right now is to explore proper weighting without ankle weights first, and see if it is something I actually need. I am amazed at how often I find my 'plan' dismissed and told that I should just start using ankle weights right away.

What's the deal? Is there some unwritten rule that drysuit diving requires ankle weights?

 

[Crush]

I have 50 dives on my drysuit and have never used ankle weights.

I am speaking as a novice diver, but I can't help but think that proper weight placement (top cam band, bottom cam band, and belt) so as to achieve good trim would obviate the need for ankle weights.

 

[Paco II]

I probably should have added to my op that I don't believe ankle weights are required in any way. I just find it interesting that something that began as a method of resolving a certain issue (floaty feet) has taken on a life of its own and reached the level of being an 'absolute' for a lot of people.

 

[barrmust]

I do not use ankle weights. I have never need' them to trim out. My dive partner uses ankle weights to trim out correctly. It will depend on several things. Your body, your suit and your other gear. You need to go in with all the gear you carry and see how you trim out.
Simple things make a differance. How do your fins float or sink, how much air is moving to your feet, ect. If your feet are floaty then you may need to shift your tank or try ankle weights. If you can get away without using them great but you wont know till you have some more dry dives to find out. You just need to do what works for you and not worry about what other people think.

Russ

 

[CardShark]

My take : there's normally no need to resolve a technique issue with equipment.
Personally, I don't need the extra drag / inertial disadvantage / expense of ankle weights.

That said, I know a diver with ~ 6,000 dives who wears them.

 

[scubamarketing]

The reason most dry suit divers know they're likely to get air in the feet. Most suits have a fairly large "shoe" so people can wear insulation, so they turn into lift bags when air flows into them. This puts a dry suit diver in one of their most dangerous situations, a feet first ascent. Since most air dump valves are on the shoulder or wrist, this now makes those exhaust points as far away from the air possible. As the diver floats feet first to the surface, the air expands to a point where I've seen with students, the boots inflate so much their fins pop off. Since the solution to a feet first ascent is to kick into a ball and roll out the correct way, not having fins since they popped off. Now, that's worse case scenario, but a distinct possibility. I wear them, I've tried dry suit diving without them and find it far more difficult, just another thing I have to keep track of. I didn't wear them with my wetsuit, so I don't think it has as much to do with floaty feet than principles of buoyancy.

 

[Jorgy]

Learn to dive without them......

I think that for most folks it is a matter of adjusting trim without them....

Move more ballast higher up on the BC/BP......so you can still trim out....

At least for me adding # pounds of weight at the end of your leg makes finning more difficult....

So learn to dive without them.....

M

 

[Paco II]

What I expected to hear from people was something more like 'start without, then add if necessary.' But I am just really surprised at how many people have told me to just use them from the get go, like they are just a given.

 

[doctormike]

As newscubamarketing said, this is all about avoiding inversion, not really trim in the traditional sense that we think of it. Yes, you can certainly learn to dive dry without them, but that doesn't mean that even an experienced dry suit diver can't get into the inverted situation (you need to train to roll out of it, etc..).

Tight fitting dry suits (like the White's fusion) and gaiters ("sleeves" that go around your calves) help with this, and are a reasonable alternative. They keep the air space around your lower legs and feet to a minimum. On the other hand, I use ankle weights and I have had no problems with them - they are very comfortable and don't really impact on my mobilty, IMHO. Pretty cheap, too, when you think of them as a percentage of your dry suit cost..!

 

[Crush]

newscubamarketing has way more logged dives than I do, so bear that in mind when you read my disagreements with her post.

Personally I don't care either way if anyone wears ankle weights. I am just not convinced that they are necessary for drysuit diving. Do whatever floats your boat (horizontally).

The reason most dry suit divers know they're likely to get air in the feet. Most suits have a fairly large "shoe" so people can wear insulation, so they turn into lift bags when air flows into them. This puts a dry suit diver in one of their most dangerous situations, a feet first ascent.

I believe that the entire drysuit is a lift bag. However, I don't think that, holding proper trim, your feet lift any more than does any other part of your body. When diving a 3 mm wetsuit I have the same amount of weight on my top and bottom cam bands, none on my ankles. When diving a drysuit with thin undergarments I have the same amount of weight on my top and bottom cam bands, none on my ankles. The drysuit requires more weight total, but not different weight placement. Net effect: the drysuit provides more buoyancy, but it is not concentrated at my feet.

I agree, however, that a feet-first ascent is bad.

Since most air dump valves are on the shoulder or wrist, this now makes those exhaust points as far away from the air possible.

I agree - my boots do not have exhaust valves.

As the diver floats feet first to the surface, the air expands to a point where I've seen with students, the boots inflate so much their fins pop off. Since the solution to a feet first ascent is to kick into a ball and roll out the correct way, not having fins since they popped off. Now, that's worse case scenario, but a distinct possibility.

I am curious if your fins would ever pop off with rock boots (I doubt it).

I agree that this is a worst-case scenario, and while it is possible, it is not likely.

The point is that the problem was caused by diver failure - you got caught feet-up and failed to react before your boots popped off. Ankle weight aren't necessary to solve the problem, but attentiveness and proper weight placement (which I believe can be achieved without ankle weights) are.

I don't think it has as much to do with floaty feet than principles of buoyancy.

Perhaps my drysuit was made with a smaller-than-average foot volume?