There are only an estimated 10,000-25,000 blue whales believed to be still swimming the world's oceans, and lucky guests on International Expeditions Galapagos Islands cruise last week had a memorable encounter with these giant creatures. Blue whales are the largest known animals to have ever lived on Earth, so there was no doubt what they were seeing when guests observed this whale’s huge spout. Expedition leader and naturalist Boli Sanchez — who shot this video — shared his thoughts.

“It was the morning of Day 2 on our Galapagos cruise, and we were aboard Zodiacs in the northern part of Isabela Island. Our boats we just about to cross the Equator line when we saw a huge spout — I had no doubt it was a blue whale! Our guests and the guides were so excited because we have not seen a blue whale for two years. Imagine, seeing the biggest creature in the world so close to our Zodiacs. Simply amazing! Of course, everyone now has lots of pictures and wonderful memories of our Galapagos expedition."