Most California surfers spend their sessions stressing about small waves, crowds, or maybe even sharks – given the exceptionally high volume of toothy predators lately.

Way out to sea and aboard his downwind foil, Tavis Boise, however, has bigger problems.

Just weeks after filming a viral encounter involving a hydrofoil surfer being chased by a large shark off Santa Barbara, Boise found himself at the center of another wildlife encounter—this time involving two creatures considerably larger.

It was a mother gray whale and her calf.

The incident occurred during an after-work downwind foil session off the coast near Miramar Beach. Boise was cruising along about a quarter mile offshore when something unusual caught his eye.

At first, he spotted what he described as a massive sea lion feeding nearby. Then he noticed two enormous shapes emerging from the water.

"They're really big.…