This is one of those films that really does resonate. Using some phenomenal archive photography of the realm beneath the sea, Sir David Attenborough narrates a story of devastation, desperation and ultimately optimism as he takes us on a journey around the globe evaluating the damage caused to the Earth’s oceans by a mankind who has treated this vast resource with contempt ever since industrialisation enabled us to ignore the protective forces of nature and pretty much fish at will. Some of the imagery here is truly breathtaking. It’s beautiful, colourful and vibrant with creatures that look every inch as if they came straight out of science fiction. It’s not just the sheer variety of life that we see that takes your breath away, though. The effects of the trawlers scarifying the scallop beds or the coral reefs renders them akin to a waste ground after a bomb has been dropped on it. The ruin is profound and quite frankly upsetting. Our continuing reliance on cheap and abundant food for ourselves and our pets is compromising the very existence of species that have existed in harmony with nature (and even humanity) for millennia. In his usually potent but understated manner, Sir David makes his points without resort to hyperbole and superlatives and as he lays out the scale of this problem before us he offers us hope that there is still time, should we take a longer-term view, for us to leave well alone and allow this crucial part of the planet’s infrastructure to recover and assist with the fight against global warming. The message is clear as a bell, but it isn’t laboured by the dialogue. It is illustrated by odd looking crabs, seahorses and magnificent blue whales. The production is top class and as an educational piece of cinema, this will take some beating - especially if you can catch it all on a big screen.