We know more about other planets than our own, and today, I want to show you a new type of robot designed to help us better understand our own planet. It belongs to a category known in the oceanographic community as an unmanned surface vehicle, or USV, and it uses no fuel. Instead, it relies on wind power for propulsion, and yet it can sail around the globe for months at a time. So I want to share with you why we built it, and what it means for you. A few years ago, I was on a sailboat making its way across the Pacific, from San Francisco to Hawaii. I had just spent the past 10 years working nonstop developing video games for hundreds of millions of users, and I wanted to take a step back and look at the big picture and get some much-needed thinking time. I was the navigator on board, and one evening, after a long session analyzing weather data and plotting our course, I came up on deck and saw this beautiful sunset, and a thought occurred to me; how much do we really know about our oceans? The Pacific was stretching all around me as far as the eye could see, and the waves were rocking our boat forcefully, a sort of constant reminder of its untold power. How much do we really know about our oceans? I decided to find out. What I quickly learned is that we don't know very much, and the first reason is just how vast oceans are, covering 70 percent of the planet, and yet we know they drive complex planetary systems like global weather, which affect all of us on a daily basis, sometimes dramatically. And yet, those activities are mostly invisible to us. Ocean data is scarce by any standards. Back on land, I had grown used to accessing lots of sensors, billions of them actually, but at sea, in situ data is scarce and expensive. Why? Because it relies on a small number of ships and buoys. How small a number was actually a great surprise. Our National Oceanic and Atmospheric Administration, better known as NOAH, only has 16 ships and there are less than 200 buoys offshore globally. It is easy to understand why. The oceans are an unforgiving place, and to collect in situ data, you need a big ship capable of carrying a vast amount of fuel and large crews, costing hundreds of millions of dollars each, or big buoys tethered to the ocean floor with a four-mile-long cable and waited down by a set of train wheels which is both dangerous to deploy and expensive to maintain. What about satellites, you might ask? Well, satellites are fantastic, and they have taught us so much about the big picture over the past few decades. However, the problem with satellites is they can only see through one micron of the surface of the ocean. They have relatively poor spatial and temporal resolution, and their signal needs to be corrected for cloud cover and land effects and other factors. So what is going on in the oceans? And what are we trying to measure?