Last thing first:
I am just wondering about the general benefit of these weights...
In pool it's to keep you a) down in water, and b) streamlined. If your legs go up or down it ads to the drag...
In depth it's about a) not being too light when going down, and not too heavy at bottom (lungs are compressed, and the buoyancy has decreased). And b) having the weight beneath the lungs/buoyancy makes you fall straight down in a streamlined position going heads down (otherwise lungs might want to go up, and legs down).
I am building the neck weight soon, but I am curious how to determine the exact weight I need to use. Any suggestions to make this easier.
Not sure what you mean by "easier", the easiest way is relative. I know and can think of different ways:
Have lots of interchangable small weight OR just go by ½kg intervals... (so have at least two ½ kg - one for head, one for waist, for the measurement). Find a rough estimate to keep you down. At the end of a glide you will allways go up or down, but you shold be able to glide for... hmm.. maybe 10-20 sec.
Pool:
Method 1) Push off from wall or kick a few times with fins, down at app. 1m. See if you sink or float in general. When you found the app. weight, start to move it around from and to neck/waist to see what happens. This might even teach you what it feels like, when weight is realy unevenly distributed. Repeat and repeat until that perfect feeling of endless glide...
Method 2) Attach two spring weights to something heavy on the bottom, and attach it to belt and neck (do have a partner here, for reading the springs, and safety).
Method 3) If you have only one spring weight, just measure it one at a time
For depth it's easier:
Just go down the line, and see at what depth you are neutral, and adjust. For safety be neutral deeper (so that you wil float deeper, and easily go to surface) fx 15 m. But as mentioned it depends on the depth you wanna do. If only going to 5 m, and that's the bottom or near, you can be neutral at taht depth. What you don't want to, is being surprised at depth because you are suddenly too heavy.
Also, do I need to be chest high while doing dynamics to benefit from the neck weight?
Don't understand this question. What do you mean.
Would one use the same weight when doing constant weight dives?!
Depends on the weight
Normally people have a heavy for the pool (neutral at 1m fx) and a lighter for depth (neutral at 12m fx). But it all depends on the suit, and the target depth.
Keep two things in mind:
- If you get a perfect weight for pool (both neck and waist) it is perfect for that suit, with those fins, with that amount of air... If you change anything, the needed weighting changes (but not nescessarily a lot, depending on the changes).
- If you change one end, the other might need to be changed also (neck/waist) because you've changed the system.
