We were staying at a beach house on the northern shore of Anahola Bay where there is a big reef about 100 metres off shore. The house was generously supplied with toys to play about with in the sea. There was a double surf kayak. I took it out to the reef and spent most of my time in the sea trying to put the kayak the right way up. Then I tried to make it through the gap where (if you are any good with a surf kayak) you can get from the sea into the mouth of the Anahola Stream when the tide gets higher than the sand bank that normally covers it. Some experts on the beach watched me roll over repeatedly and eventually gouge out a deep channel into the river mouth using no tools other than my head.
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