CRITTER: The giant corals of Wainiha Bay

There is a secret garden of gigantic corals along the North Shore of Kaua‘i that is rarely visited by humans. These corals, which are the size of a school bus, are growing in a very unlikely place that people drive by everyday without even knowing they are there and the corals are over 1,000 years old.

Wainiha Bay is located between Hanalei and Tunnels Beach and is a very unfriendly place if you like to dive, snorkel or surf. Wainiha means “wild waters” and due to the direction the bay is located, huge surf and persistent wind hammers the bay night and day.

Many of the locals that live in the town of Wainiha told me long ago to never dive there because the bay is so rough and there are large tiger sharks that patrol the bay.

After many years of driving by the bay on my way to Tunnels to go diving, I decided it was time to really see for myself what mysterious creatures call Wainiha Bay home.

Before scuba diving a new spot I always snorkel it first to see what the currents are like and how safe it is to scuba dive the spot, so I picked a rare calm day in Wainiha with little wind and no surf in the summer.

I started snorkeling from the point on the Hanalei side of the bay crossing the entire bay to the Tunnels side. I figured the snorkel would take me about 30 minutes and the water was crystal clear. I left the rocky shore and within five minutes was in water so deep I could not see the bottom. This was very odd because I was not far from shore and it should only be about 20 feet deep.

It turns out that the Wainiha River has dug out a huge hole in the bay that is 80 to 100 feet deep. As I snorkeled over the top of the deep blue hole, I was wondering what lives down there and was excited to explore it later on.

At about halfway across the bay, I started to see something massive that was light yellowish brown. Along North Shore there is very little coral cover due to the large surf except in calm sheltered places like the Tunnels Lagoon, so I was confused.

As I got closer to the Tunnels side, I was just stunned with what I saw. There was a ridge coming up from the deep water and the underwater cliff was about 50 yards long and covered with gigantic lobe corals. These corals are 20 feet tall and 30 feet wide and must be thousands of years old because lobe corals only grow about 2 to 3 inches a year.

Why was this huge lobe coral garden growing right in the middle of this wild choppy bay, when these corals normally grow in sheltered lagoons? I decided to scuba dive the spot and figure it out, so a week later I did my first dive in Wainiha Bay off of my yellow kayak.

The wall of mound corals starts about 100 yards offshore and ends abruptly as the reef gets shallow at the outer edge of the bay. The river carved a deep hole right in the middle of the bay and the ongoing huge surf breaks on each side of the bay. This causes a calm spot in the middle of the bay at 40 feet deep even though up above the sea surface can be very windy and rough.

I nicknamed the lobe coral garden the “aquarium” because of the thousands of fish that congregate in this calm underwater oasis. Since my original dive there I have done over 100 dives documenting the growth of these giant corals and I have taken a few other divers out there with me.

Even the professional divers look at Wainiha Bay and say it’s not doable because it just looks so violent, but when they drop down to this unique underwater garden they are blown away. The experience of diving at the aquarium is like standing in the eye of a hurricane where it is very calm, but all around you nature is blasting away at the environment.

The reefs along the North Shore are less studied than the moon and there are still many places that have never been visited by humans. I have done over 500 scuba dives along North Shore and am editing an entire movie series to show in our schools to educate our kids about this special place we call home.

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Terry Lilley is a marine biologist living in Hanalei Kaua‘i and co-founder of Reef Guardians Hawai‘i, a nonprofit on a mission to provide education and resources to protect the coral reef.