A neck weight is the most efficient way to stay neutrally-buoyant while swimming under water, with or without fins.
The air in the chest makes the top part of the body very floaty. A weight belt helps, but you will be fighting your way through to stay submerged because your bottom sinks and your top floats. You want to be as streamlined and horizontal as possible and neither sink nor float. Having most of the weight around the floaty parts evens out the buoyancy. Depending on your body shape and composition you may still need to use a small weight belt, but the neck weight makes all the difference.
Neck weights are unique to freediving and are not normally sold by spearfishing shops. You can make one yourself or ask another club member to make it for you. A more expensive alternative is to order a purpose-made neck weight like the famous Lobster.
D.I.Y.
Most club members make one DIY-style. It's easy to make and works just fine for training and competitions.
Watch how streamlined this diver is in the video below. Kathryn is using a DIY neck weight and a weight belt around her hips. The neck weight may be hard to see. Pay attention to the black tube around her neck.
Pros:
- the cheapest option
- does the job
- made to suit you
Cons:
- not easy to change the weight
- you have to spend an hour or so making it
You can purchase the kit consisting of lead or stainless steel shot, clips and a bicycle tube from AFC. It has everything you need to make a good neck weight that will last you for years.
If making it looks unattainable for whatever reason, one of our members may be able to make it for you in exchange for a good PB.
The Lobster
This is a neck weight used by many top freedivers. We have several club members using it as well.
Pros:
- very streamlined
- adjustable weight for different conditions, e.g. a new wetsuit or fresh water vs salt water
Cons:
- price
Orders: lobsterweight.com
Also check a similar high-end neck weight from Alchemy.