We started by looking at beach-themed science with some friends at our house. We talked about why a sea breeze blows from the sea to the land with the help of this demonstration. The sun (grapefruit) warms the sea (ice pack) and the land (warmed sand) at different rates, resulting in different air pressure. The wind blows from high to low pressure to try to equalise it.
We also talked about different kinds of waves and demonstrated that water molecules move in a circular motion within a wave, by making waves in a tub of water containing a floating object. The object bobbed up and down and returned to much the same starting place. I used this page to help with the explanation (http://legacy.mos.org/oceans/motion/wind.html).
We watched a BBC class clip (http://www.bbc.co.uk/education/clips/z4mn34j) showing how beaches are formed and the stages of rock erosion and a YouTube video about tides (http://youtu.be/5ohDG7RqQ9I), before having lunch and heading down to a local beach in Whitley Bay for some real life investigation with our friends.
Lots of rocks were collected and we brought a bucketful home to examine in detail tomorrow. We saw the different stages of erosion we had seen in the video at home. Harry liked these red ones in particular. We also collected sand and sea water to use tomorrow and observed the tide coming in during our long visit - the area below was completely covered with water when we left.
General beach fun was had for several hours too - jumping in the waves, drawing in the sand, excavating tunnels and building seaweed 'forts'.
And, erm, licking rocks!! Peter kept dipping the rock in the sea and licking it. Surely only a three year old would think to do that!