Where Do These Ocean Giants Disappear To? | North Atlantic: The Dark Ocean | 4K UHD | BBC Earth

Basking sharks can grow to be up to 10 metres long and can weigh up to 5 tonnes. Despite their massive size, they are only ever seen for a few weeks per year, when they feed on plankton in the sunny waters during the spring months. Which begs the question, where do they go for the rest of the year?