– David Rockefeller, Jr. is a philanthropist and CEO of Around the Americas and Chairman of Sailors for the Sea. Any views expressed here are his own. –

When the Ocean Watch set sail from Seattle last May at the launch of our Around the Americas expedition, our greatest challenge was to make Americans start thinking about health of oceans. For too long, we have been taking our rich seafood supplies and scenic seascapes for granted.

One year and 28,000 miles later, and now with the massive BP oil spill, much has changed.

While I’d love to say that our expedition is responsible for finally turning around the slow drip of public concern for ocean health into a steady flow, I am fairly certain that the continuous flow of oil spilling into the Gulf of Mexico is, unfortunately, driving home what the captain and crew of Ocean Watch have been saying all along.

The fact that our oceans are not too big for one person to damage is becoming clearer with each passing day. In just one month, we have witnessed the largest oil spill in the history of the U.S., with the full repercussions yet to be seen.

We know our Gulf seafood supply of shrimp, oysters and blue crab will likely be damaged for generations to come, to say nothing of the sea turtles, sea birds and other wildlife that are already suffering.

David Rockefeller, Jr., a philanthropist, is sponsoring a year-long sailing trip around the Americas looking at environmental impacts on the oceans — from melting ice to fish farms. Here are his thoughts after stepping aboard the voyage for two weeks around Cape Horn.  The views expressed are his own.

For climbers, there is just one Everest.  For sailors, there is just one Cape Horn – the southernmost piece of the American Continents, and often the windiest, most treacherous place in all the oceans.

Eight of us voyagers recently sailed around “the Horn” on a boat called Ocean Watch.  We flew a billowing spinnaker with a graphic of the two American continents and a mainsail sporting our own expedition logo, “Around the Americas, 2009-2010.”  A flock of thirty albatross rode the surprisingly benign ocean swells.  Two breakfasting cruise ships gave scale to the forbidding cliffs.

Ten years ago I sat on the Pew Ocean Commission and learned in startling detail that our boundless seas had become imperiled by the careless behavior of a rapidly expanding human population and its post-industrial habits of taking, making and disposing.

As a result, I determined to do something to let other sailors know what I had learned: for example, that hyper-efficient fishing vessels had removed 90 percent of the large fish from the world’s oceans in just fifty years.

I created Sailors for the Sea, a non-profit organization designed to turn recreational boaters into Ocean Stewards.  Then, four years ago in the port of Naples, Italy – Mark Schrader, David Treadway and I (all members of the crew that just rounded Cape Horn) came up with an idea to circumnavigate the two American continents by sail and draw attention to the serious health challenges faced by the world’s oceans.