The man with the striped tarp at Lamai Beach, and my dry book

The rain came in at Lamai Beach just as I was setting up to read. A man with a big striped tarp walked over, propped it up on two sticks in the sand above my towel, and went back to his own table without a word. When the rain stopped he came back for it, nodded, and left. The whole thing took six minutes. I think about people who simply do things. My book stayed dry. I finished it that night. I do not remember the ending.