Returning visitors often ask why the tide isn’t the same as it was when they were last at FMR a week, a month, or a year ago. The short answer is that tides are caused primarily by the motion of the moon. The KQED Quest web site has a wonderful video explaining how the pull of the moon creates high and low tides, complete with an animation. It’s less than seven minutes long and well worth watching! Just follow this link and click the “play” button on the video.