California whale watchers witnessed the moment a gray whale gave birth to a calf on Monday and could not believe their eyes.

The group was enjoying an excursion off the coast of Dana Point with Capt. Dave’s Dolphin and Whale Watching and recorded the special moment from the safety of their catamaran, the Los Angeles Times reported Wednesday.

Initially, the gray whale was not swimming in a straight line and then began going in circles. Everyone became more alert when they saw blood in the water, which was usually not a positive sign, according to Stacie Fox of Capt. Dave’s.

“But I was like, I bet this is a female giving birth. I started yelling that to my captain. I was taking pictures,” she added.

The company shared images Monday of the whale and what appeared to be the blood in the water:

Fox told the newspaper, “It is kinda hard to put into words how amazing it was. I’ve always wanted to see a whale birth but I never thought it would actually happen.”

Video footage shows the calf moving alongside its mother as those recording the moment watched excitedly. At one point, the cow approached one of Capt. Dave’s boats:

“This is a first for all of us,” someone told the whale watchers over a loudspeaker. “We’ve never seen this actually happen,” he added.

The Times report said the whales are currently migrating to the lagoons in Baja California, Mexico, where they are known to give birth.

A gray whale calf is approximately 17 feet long when it is born, per the Monterey Bay Aquarium.

“A newborn calf is dark, wrinkled and barnacle-free. In the warm calving lagoons in Baja California, a calf remains in close contact with its mother, often swimming onto her back or tail flukes,” the aquarium’s website reads.

In another post on Wednesday, Capt. Dave’s shared more footage of the incredible moment and said, “We can’t get enough of the newborn calf!”

“In this previously unshared footage from Monday’s sighting, the calf swims in circles with mom in tow. The little one still hadn’t mastered how to use its flukes for propulsion. It’s learning quickly though!” the company noted.