"Depending on what you mean by frequent. The moon is in syzygy about twice a month. One of the superstitions associated with this one is that tides are somehow more extreme during the moon's syzygy."

This is not a superstition--these are the spring (extra high) and neap (extra low) tides that do in fact occur at the moon's syzygy.

The only real way to look younger is not to be born so soon. -- Charles Schulz