Imagine a tube, 20 feet in diameter (the size of a house) filled with seawater, floating in the sea. Now imagine another tube inside that tube, maybe 5-10 feet in diameter, filled with air. So the air-filled tube floats above the water, like a beach ball. But the air-filled tube can’t go anywhere, because it’s inside the water-filled tube.
Imagine that these tubes extend tens of miles, parallel to the shore, but several miles out to sea. When the hurricane comes from way out at sea towards the shore, the water stacks up behind the air-filled tubes. Some flows over it, but not much. The air-filled tubes get pushed towards shore, but because they’re inside the water-filled tubes, the tubes move very slowly (say 1 mile per hour). In contrast, the hurricane is moving towards shore more rapidly, say 10 miles per hour. So eventually, the eye of the hurricane passes over the tubes. As long as this happens before the tubes get pushes completely to shore, the water behind the tubes just flows back out to sea, and the storm surge is minimal.
The air-filled tube would be filled with a giant compressor/fan. The water-filled tube would get filled by dragging the tube behind a ship, like a fishing net. The most important aspect of the design is that it's portable, and can be deployed essentially anywhere with a couple days' notice.