Really low tide. Jetty to breakwater.
Full moon.
These are called neap tides. When the moon is full or new, the gravitational pull of the moon and sun are combined. At these times, the high tides are very high and the low tides are very low. They occur when the Earth, the Sun, and the Moon are in a line.
Opps. This post got it backwards. Spring tides occur when the moon is new or full and are the bigger tides.
During full or new moons—which occur when the Earth, sun, and moon are nearly in alignment—average tidal ranges are slightly larger. This occurs twice each month. The moon appears new (dark) when it is directly between the Earth and the sun. The moon appears full when the Earth is between the moon and the sun. In both cases, the gravitational pull of the sun is “added” to the gravitational pull of the moon on Earth, causing the oceans to bulge a bit more than usual. This means that high tides are a little higher and low tides are a little lower than average.
These are called spring tides, a common historical term that has nothing to do with the season of spring. Rather, the term is derived from the concept of the tide “springing forth.” Spring tides occur twice each lunar month all year long, without regard to the season.
Seven days after a spring tide, the sun and moon are at right angles to each other. When this happens, the bulge of the ocean caused by the sun partially cancels out the bulge of the ocean caused by the moon. This produces moderate tides known as neap tides, meaning that high tides are a little lower and low tides are a little higher than average. Neap tides occur during the first and third quarter moon, when the moon appears “half full.”
http://oceanservice.noaa.gov/facts/springtide.html