Somewhere off the coast of Maui, 55 meters down, a pod of giants patrols the ocean. Those giants are humpback whales, some of the most distinct creatures on earth. Their complex songs can last for 20 minutes, they hunt krill and fish with nets of air bubbles, and they can grow to 50 feet in length and weigh nearly 80,000 pounds.

This video features a close encounter, the kind that makes other divers jealous. To get this close, the divers had to get lucky. Also, they had to go deep: more than 150 feet deep. And to get there, they had to use helium in their air mix to mitigate the risk of nitrogen narcosis. Helium is often used when diving at depths below 130 feet. Also, because it is lighter than air, helium speeds the rate at which soundwaves travel through your larynx. Thus the divers’ high-pitched squeals of excitement.

Or maybe they’re just really excited.