Erik van Sebille, a physical oceanographer at Utrecht University, Netherlands, attended the event and liked what he saw. Two years ago, he says, Ocean Cleanup seemed like a group of single-minded engineers out to save the world. "A lot of scientists thought they were stubborn," he says. "Yesterday they showed that there are not afraid to change their approach. The radical rethink, ditching the mooring--I think that's great. And they've become more scientifically aware." From an oceanographic perspective he says the new design "makes sense in the first order," but he would need to see more details before being convinced that it will work as intended.