A passage is given with the question following it. Read the passage carefully and choose the best answer to the question followed out of the four alternatives.

The instructor's rules were simple. Breathe through your mouth, not your nose; else the mask will fog up. Easier said than done; I got it wrong many a time. But once you fought habit and got the hang of it, the panoramic underwater world revealed itself to you with high-definition clarity.

Led by him, I slowly peered through the mask into what till then was crystal-clear water, shimmering in the sunlight. I saw pebbles, send and my fluid shadow. I was in Nemo's Universe. Sea cucumbers, sea anemone, clown fish, star fish, sea horses, parrot fish, butterfly fish and a bevy of colourful salt water fish swam past. A shoal of canary-yellow fish did a merry dance and another with vibrant blue fish followed it. They were oblivious to the snorkelers who struggled to take in the sight of the world so beautiful, so colourful, and resist opening their mouth, beautiful in amazement; the tube would fall off!

The writer is describing her experience of which activity?

• fishing

• snorkelling

• boat ride

• long distance swimming