Though you may think that SCUBA divers would automatically sink to the bottom of the sea due to the weight of their tanks, this is not really the case. Most divers have to use dive weight belts to help them be able to dive deep into the water.
A dive weight belt is bought along with the rest of your SCUBA gear and can be found at any SCUBA shop or you can easily find them for sale online. These belts have spaces in them where weights can sit. Depending on your weight, you will add in several pounds of weights to your belt so that you will be able to dive correctly.
The weights can easily be dropped out of the belt in case an emergency arises and you need to quickly go to the surface. Be sure to test out your belt in a swimming pool before taking it into the ocean for the first time. You should practice dropping out the weights in case you ever need to do so when you are diving.
Typically, divers will need 4 pounds of weights for every 33 pounds that they weight. This may vary slightly from diver to diver, but this is a good general standard. Once you practice with your dive weight belt, you should be able to tell whether or not you will need to use more or less weights.
There are other devices you can use to accomplish the same thing aside from the weight belt. You can also get a weight harness, which is essentially the same thing, however it has shoulder straps that are used for supports.
There are also backpacks that can be used as weight devices. These usually have a pull cord that you can use in case you need to drop weights during an emergency. Dive weight belts are typically made of a nylon material so that they are very durable, yet easy to wear.
Some weight belts are even made of rubber. You can find weight belts in several different materials, but most professional divers use a nylon belt. No matter which style weight belt you choose, be sure that you take all the proper safety precautions before you dive.