What is a barnacle?
Like a crab Barnacles are crustaceans, however a barnacle lives most of its life attached to a rock using one of its arms to sieve food from the seawater.
Why watch Barnacles?
They are easy to see and great to watch under water. At low tide when you see them on the rocks they are not all that active, but they come to life once they tide comes in and covers them.
What do I need?
A hot day and a snorkel mask or goggles. Make sure the sea is calm as you do not want to be pushed against the rocks. Simply put on the mask and get close to a part submerged rock, look carefully and you will see all the barnacles doing a sort of Mexican Wave as they sift the water for food.