There are significant health benefits to trying new things, whatever the activity – and there is always more to learn

There is a paradox to being 20 metres under the ocean. It is a place of calm and wonderment. I am immersed in a foreign world, with a new watery sky above me. There is a sense of serenity, blissful peace as countless colourful fish glide past.

Only the tranquillity is deceiving. As a novice diver, my mind ticks over in hyperdrive. All that stands between me and an agonising fate is the tank of oxygen on my back (and, hopefully, the dive guide’s spare air).