Concept of Neutral Buoyancy in Scuba Diving
Buoyancy & the Breath
Ever wonder how we manage to keep tonnes of Kilograms afloat? Or Why NASA has a SCUBA facility? It all started in Ancient Greece with a concept “floated” around by Archimedes. Simply put, his principle stated that an object is “buoyed or pushed up” according to the weight of water it displaces. Following this, the object starts to float, sink or becomes “Neutrally Buoyant” (technically weightless).
This brings NASA into the picture. Their Neutral Buoyancy Lab (NBL) acclimatises astronauts to the weightlessness felt in space! Luckily for us SCUBA divers, we can experience this closer to home.
We all know that a balloon filled with air shrinks as you take it deeper into water and expands on its way up to the surface again. And this applies to all air spaces when we go SCUBA diving. As divers, we use 2 variables to slip into this weightlessness or Neutral Buoyancy. An inflatable/deflatable jacket known as the BCD (Buoyancy Compensation Device) and our very own Breath. Breathing in expands the lungs making us “lighter” whereas exhaling leads to a gentle “sink” and each is checked or reversed by the other. Somewhere in between is the magic of complete weightlessness.
First time divers are often astonished on their first encounter and many return to the wonder of the experience. Often, I yearn to be breathing underwater once again suspended in a drop of Blue. I encourage all you divers to share your first encounter with weightlessness in the comments below.