This was high tide in Dumfriesshire this lunchtime. It is the New Moon. The Moon is lined up with the Sun on the same side of the Earth. They are both pulling on the water. The Sun is a lot heavier but a lot further away. This, coupled with high onshore winds, meant that the sea was almost onto the dunes. The relative pull of each heavenly body is proportional to its mass divided by the distance away squared. For the Moon, this is 7x10^22/(3.8x10^8)^2 = 4.8x10^5. For the Sun it is 2x10^30/(150x10^9)^2 = 8.8x10^7. The pull of the Sun is actually about 180x bigger than the Moon. However, it is not this that affects the tides. It is the difference of pull from one side of the Earth to another. That's going to need further calculation.
