Fear

As a kid, and even now, I have had issues with water. I love being in the rain with puddles the size of small ponds, but being in lakes or other large bodies of water scare me. Well, one year when my parents and I were camping with my Auntie Bonnie it started raining, hard. It kept raining and raining for two days. After a full day of rain, the whole campsite was flooded. We were trying to make our food while standing on the picnic table while wearing garbage bags, in my case storage bags, over our legs. The water was almost up to my knees (it only got to my parents' shins). I was trying to keep my cool, like the adults were but I was scared. Eventually my parents decided that we could go home. I was 8 or 9 years old then and we have not been camping, as a family, since.
The boys in Golding's The Lord of the Flies don't seem to have the same problem that I had, they all seem to enjoy the water. Pretty much the only fear mentioned in the book is the "beast", which is at one point thought to come from the water:

Jack listened to Percival's answer and then let go of him. Percival, released, surrounded by the comfortable pressence of humans, fell in the long grass and went to sleep.
Jack cleared his throat, then reported casually.
"He says the beast comes out of the sea."
The last laugh died away. Ralph turned involuntarily, a black, humped figure against the laggon. The assembly looked with him, considered the vast stretches of water, the high sea beyond, unknown idigo of infinate possibilitiy, heard silently the sough and whisper from the reef." (88)