It’s six o’clock in the morning. You’re standing on a dock in Oslob, a small fishing village in the Philippines. You rub your eyes as a man in charge goes over the rules. No touching. No riding. No flash photography. No sunscreen. Keep at least 5 meters (16 feet) away from the sharks at all times. Normally, you wouldn’t need someone to remind you to keep your distance from a shark. But, today is not a normal day.

You grab a mask and snorkel and put on your life jacket before joining other tourists who hop aboard a large, thin canoe. The canoe is equipped with floats to provide better balance in the water. The captain paddles out 45 meters (about 150 feet) from shore, leading a long line of canoes like yours.

A few of the boat captains toss buckets full of shrimps into the sea. It doesn’t take long before you see what you’ve been hoping for. Cruising slowly through the clear waters, you see them. They are the biggest fish in the oceanwhale sharks.

Tourists watch whale sharks in the Philippines.

Tourists learn about whale sharks before diving in to swim with them.

The captain tells everyone it’s okay to get in the water, but to stay out of the way of these gentle giants. You jump in, holding onto the side of the canoe. With your head underwater you can see an immense shark swim past. It has a wide mouth, with a smatter of white spots on its huge head. It has a checkerboard pattern of larger white spots down its back and sides.

It’s so big. You feel humbled. As another shark comes by, you pull out your waterproof camera. Click. Click. Click.

A group of tourists jump in the water to swim alongside and take pictures of a whale shark.