August is the low point of the swell year and the high point of everything else. The storm track is at its furthest north, what reaches the coast is small, and the beach that had room on it in May carries a surf school every hundred metres.
Something happens underwater that nobody watching the beach can see. The first real swells of the season arrive at the end of the month and push the sand back into bars, and those bars are what produce September and October. The month that surfs worst is the one that builds the year's best waves.
The Landes beaches carry a hazard in August, and it is not the wave. Baïnes are the channels that fill and drain between the sandbars, they pull hard on a falling tide, and they catch swimmers far more often than surfers. Swim between the flags, and ask which way the water is moving before you paddle out.
