BBC Earth:

The world is an amazing place full of stories, beauty and natural wonder. Explore the official BBC Earth YouTube channel and meet the animals and wildlife of your planet.

This is 70 hours of oceanscapes from the BBC broken up into ten hour chunks of seven videos: coral reefs, coastlines, deep ocean, open ocean, frozen seas, ocean surfaces, and sea forests. I don’t know that anyone needs to watch this much ocean video but the BBC stuff is spectacularly beautiful.