Perhaps the closest a human being comes to visiting another planet is to descend into the sea. In Soundings, Kennedy Warne connects his lifelong exploration of the underwater world with a global story of humanity's relationship with the sea.

Drawing on more than 20 years of fieldwork for National Geographic, he shares experiences that range from diving with harp seals under the sea ice of the Gulf of St Lawrence to following the legendary 'sardine run' along South Africa's Wild Coast; from watching turret-building ghost crabs in Arabia to witnessing the impact of dynamite fishing in the Philippines; from swimming with crocodiles in the Okavango Delta to finding seahorses on the Eastern Cape.

From myriad underwater encounters a wider conversation emerges about human engagement with the sea. One question dominates: How can we care for and reconnect with the oceans around us?