It's easier to appreciate nature when you witness it first-hand, but that's rather difficult with the ocean unless you have a submarine at your disposal. The BBC and Google have a more practical solution: they've launched a BBC Earth: Life in VR app that illustrates the underwater ecosystem on Daydream View headsets and compatible phones. You can explore environments ranging from kelp forests to deep sea trenches, and life as large as whales or as tiny as plankton.
Yes, you could sit down to watch Planet Earth II without donning headgear, but the two companies are betting that the advantages of VR will make all the difference. It's not just that you're engrossed in situations that would be difficult or impossible to record on camera -- it's that you're an "active participant" rather than a mere bystander. If all goes well, you'll have a better understanding of the aquatic ecosystem than you would by watching an ordinary documentary.