My father, Captain Jacques Cousteau, would have been 100 years old today. He was a man of undeniable charisma, a man who always achieved his objectives, a man of such single-minded determination that he would not give up on a goal until he had achieved it. His lifelong vision was to help millions of people understand the fragility of life on what he called our "'water planet."

From his famous research ship Calypso, my father was one of the first to draw attention to the devastating results of overfishing, climate change and the effect of pollution on our underwater habitats. He became a global ambassador for the sea, a kind of spiritual guide for the environment.

He would be heartbroken at what is taking place in our seas today, especially the catastrophic oil spill in the Gulf of Mexico. One of the memories I carry with me to this day is of my father standing on the deck of our wind ship, Alcyone, looking ahead to the legacy he might leave behind. He issued me a challenge that belonged not only to me, but to all who are determined to protect our seas. "It is you, Jean-Michel, who will carry the flame of my faith." Yes, it is on me, and on all of us, to carry on the work of this brilliant, passionate man in protecting our natural resources and to acknowledge the incredible privilege we all share on Planet Ocean.

The more I look back on my father's life and work, the more I realize what a visionary he was, even though he would not have used that term to describe himself. He was a pioneer who broke barriers with his inventions such as the aqua-lung, scuba diving apparatuses and submersibles; his name became synonymous with underwater exploration, ocean photography and conservation; and I believe he did more than anyone to enlighten the world about the complexity of the ocean's ecology and the importance of preserving it.

My father introduced my brother, Philippe, and me to the wonders of the ocean at an early age, and we shared his passion for the sea and his work. One of my father's greatest wishes was to educate all children to be future stewards of the sea. To help fulfill this wish and to continue his legacy, I founded the Ocean Futures Society, a marine conservation and education organization, to open up the seas for young people and instill in them a love of the ocean in the same way my father did for me.

As the centenary of his birth approached, I have thought often about my father and the many moments we shared. Paradoxically, one of the times I felt closest to him was a few weeks after his death in 1997. I was with a group preparing for a dive, and I asked if I could have a few minutes in the water by myself. As I swam in a large kelp forest, I noticed an unusual opening in the kelp, which exposed the sandy ocean floor. The sun's rays shone through the opening, lighting up the patch of sand, like a spotlight on an empty stage. All around me were brightly-colored fish that shimmered in the sunlight like festive candles announcing an underwater fiesta. Overcome with emotion, I dropped to my knees. It felt as if my father was with me on the sun-splashed open floor. He was here, among the dazzling seaweeds, among the sparkling fish. This is the real Cousteau, I remember thinking. This is where he lived; this is where he will remain.

"People protect what they love," my father once said. My wish today, as we mark his 100th birthday, is that we redouble our efforts to love and cherish our planet and the seas that he championed.