This programme explores seasonal changes in the richest waters on Earth, where the annual cycle of the sun drives an explosion of life. Featuring an extraordinary variety of marine animals, including seals, dolphins, jellyfish and the bizarre walking handfish.

This edition explores a force so powerful that it moves oceans - the tides. All over the world tides create opportunities for marine life: giant sting rays glide on currents for a rest, the fastest snail of all surfs waves in pursuit of dinner, minute crabs play football on the beach, racoons binge and, in a unique sequence, dolphins play a deadly game of catch. For in the ocean, each turn of the tide spells life or death, somewhere.