《海底大揭秘第四季》讲述的是：　　Combining undersea exploration with innovative visualizations, DRAIN THE OCEANS reveals hidden evidence of amazing undersea mysteries.　　Not “artists impressions” but what is actually there — down to the very last rivet. And, for its fourth season, it embraces a gripping new style, telling stories purely through the words of explorers and archaeologists, putting viewers right by their side.