Watch CineCalidad. The bay is peaceful, framed by low hills in the distance. Three boys stand thigh-deep in the brown water, trousers rolled up. The biggest, on the left, is proficient in the art of stone-skimming: sending flat pebbles spinning over the water in such a way that they bounce off the surface as many times as possible before sinking. The middle boy feeds him stones from a stockpile inside his t-shirt, while the smallest looks on laughing. The skimmer throws quickly, intently, without thinking, without assessing his stone. Some stones sink at the second bounce; some skip a long way. It’s all the same to him, he must keep throwing.