Nearly all of what happens in the water is ineffable -language is no help. Wave judgement is fundamental, but how to unpack it? You’re sitting in a trough between waves, and you can’t see past the approaching swell, which will not become a wave you can catch. You start paddling upcoast and seaward. Why? If the moment were frozen, you could explain that, by your reckoning, there’s a fifty-fifty chance that the next wave will have a good takeoff spot about ten yards over and a little farther out from where you are now. This calculation is based on: your last two or three glimpses of the swell outside, each glimpse caught from the crest of a previous swell; the hundred-plus waves you have seen break in the past hour and a half; your cumulative experience of three or four hundred sessions at this spot, including fifteen or twenty days that were much like this one in terms of swell size, swell direction, wind speed, wind direction, tide, season, and sandbar configuration; the way the water seems to be moving across the bottom; the surface texture and water color; and, beneath these elements, innumerable subcortical perceptions too subtle and fleeting to express. These last factors are like the ones the ancient Polynesian navigators relied upon when, on the open seas, they used to lower themselves into the water between the outriggers on their canoes and let their testicles tell them where in the great ocean they were.
-William Finnegan; Barbarian Days