What is a brief summary of Chapter 10 of The Story of My Life by Helen Keller?

Helen Keller was excited to visit the ocean for the first time, but it frightened her when she first went in it.
When she was eight years old in the summer of 1888, Helen Keller visited the ocean for the first time during her vacation at Brewster, on Cape Cod, with a family friend named Mrs. Hopkins.  Anne Sullivan, Helen's teacher, came too, of course.

I had always lived far inland, and had never had so much as a whiff of salt air; but I had read in a big book called "Our World" a description of the ocean which filled me with wonder and an intense longing to touch the mighty sea and feel it roar. (Ch. 10)

Even though Helen Keller was blind and deaf, she enjoyed the ocean because she could feel the sand and hear the waves.  Unfortunately, when you can’t see and hear, the world can also be a scary place.  When she actually got into the water, she became very frightened of losing control.

Suddenly my ecstasy gave place to terror; for my foot struck against a rock and the next instant there was a rush of water over my head. I thrust out my hands to grab some support, I clutched at the water and at the seaweed which the waves tossed in my face. But all my frantic efforts were in vain. (Ch. 10)

Like most scary experiences, little Helen got over this one.  She was back out in the water soon. She loved the beach, including the crab that Anne Sullivan showed her.  She tried to trap him, but he got away.  Little Helen then realized that the crab was a wild creature and had a right to go wherever he wanted.  She enjoyed picturing him out in the sea enjoying himself.