3 mm wetsuit without weight in the ocean?!

[miklcct]

I put on a 3 mm wetsuit in today's lesson. The last time I didn't use one and I used no weight. Under the guidance of my instructor, I still ended up using no weight and still got good balance at -10 m. I couldn't imagine that even with 3 mm on I should still dive weightless in the ocean. How the heck is it humanly possible? Normally how many kg I need to add for every mm of my wetsuit?

Sorry if this question is idiotic. I'm still doing my AIDA 2 and just got to -16 m today.

 

[MarcinB]

Each millimetre of the full wetsuit increases your buoyancy just below the surface by roughly 1kg. At greater depth the difference will be of course lower. The amount of weights required is highly variable between individuals, and depends predominantly on the size of lungs and body composition. Even people of the same height, wearing the same wetsuit, can differ by 2-3kg in the amounts of weights they need.

 

[SubSub]

The neoprene compress and gets less buoyant with depth.

 

[Leander]

I'd say lucky you! Your dive bag will always be 2-3 kg lighter than those of your friends. Flying somewhere, or hiking to remote diving locations is easier for you. So many advantages, without any disadvantages!

A friend of mine is exactly the opposite. For his 5mm he needs 12kg to be neutral at 8-10m below.

 

[dcvf]

The rule from an AIDA instructor is :
In the water, upright, without moving, exhaling fully so in this case, the mouth should still be out of the water.
If you sink, you are too ballasted
If you don't sink in as you breathe out, you are underweight.

 

[J Campbell]

I'd say lucky you! Your dive bag will always be 2-3 kg lighter than those of your friends. Flying somewhere, or hiking to remote diving locations is easier for you. So many advantages, without any disadvantages!

A friend of mine is exactly the opposite. For his 5mm he needs 12kg to be neutral at 8-10m below.

Me too! My buddies are always telling me I have too much weight, it's dangerous. Nope! Not too much for me.

 

[miklcct]

I'd say lucky you! Your dive bag will always be 2-3 kg lighter than those of your friends. Flying somewhere, or hiking to remote diving locations is easier for you. So many advantages, without any disadvantages!

A friend of mine is exactly the opposite. For his 5mm he needs 12kg to be neutral at 8-10m below.

The rule from an AIDA instructor is :
In the water, upright, without moving, exhaling fully so in this case, the mouth should still be out of the water.
If you sink, you are too ballasted
If you don't sink in as you breathe out, you are underweight.

I liked to play with my buoyancy even before I started diving. I thought that I float so well in the sea, the water level is between my nose and my eyes when I'm upright in full lang, and I have to blow out about half of my air to start sinking.

In my shore dive lesson the instructor told me to try 1 kg first and when I reached -10 m, oh hell I was falling so fast that I couldn't even stay at the level for a second, and when I tried 0 kg I thought I was balanced. I thought I would need a lot of weights if I put on a wetsuit then.

In my boat dive lesson as the water was cooler I put on my 3 mm wetsuit. The instructor told me to put on 3 kg first, then 1 kg. I did the check more carefully and the instructor still saw me sinking at -10 m. Then he told me to remove the weight belt, and I got to -10 m again. The instructor then told me I was alright there. I was so damn surprised.

I'm thinking about what will happen if I dive in fresh water instead of the ocean without a suit and weights. In such case my neutral point will only be about -4 m even in full lung, the water level is just a few cm from my top upright at the surface without moving, and I sink immediately if I let go about 1/4 - 1/3 of my air.

 

[Leander]

I'm thinking about what will happen if I dive in fresh water instead of the ocean without a suit and weights. In such case my neutral point will only be about -4 m even in full lung, the water level is just a few cm from my top upright at the surface without moving, and I sink

Sounds like depending on the situation you might then even want to add some buoyant material just to increase the safety zone. For example when diving alone...