Ages ago, the best hunter-gatherers noted that fish and animal activity often increased when the full moon was overhead. Fishermen living by oceans, meanwhile, also noted that high and low tides followed the cycle of the moon. In more recent times, John Alden Knight in 1920 was the first to note the effect of the combined force of the sun and moon (solunar activity) on fish and game. He called the times when the moon is directly overhead and directly underfoot (on the opposite side of the earth) “major activity periods.” A period midway between each major was called a “minor activity period.”

Anglers today can find a wealth of material written about the effects of solunar activity on fish. Many authors have proposed their own approaches to interpreting solunar data. That being the case, many anglers interested in factoring solunar effects into their fishing keep it simple, noting major daily fishing periods, and they figure on an hour’s worth of peak fishing both before and after such periods (times shown in tables). These anglers also note the potential for increased fishing success on the days surrounding the full and new moon.