Many anglers use the moon phases to select fishing days and many when-to-fish tables are built around the moon phases, too. There is a little doubt that the moon affects the sea (tides), and many are of the opinion that good fishing periods are just after the full moon and just after the new moon - especially areas in the sea with shallow water. It is fact that much of the life in the sea is particularly active during these periods. This will still vary greatly and different fishermen have different theories, but we can say with certainty that moon phases are far from a fishing guarantee.