I have never hit nor seen a shippng container at sea. I have seen container ships make port (Halifax) with a stack of containers capsized on deck - clearly a few were lost. I am sure 100s of these things are lost at sea every year. The majority sink, but some, with a load of Nike shoes or reefers with foam insulation, float just at or slightly below the surface. Probably one reason we don't hear more about sailboats hitting them is that "Dead men tell no tales". It gives me chills just thinking about it. The shipping companies should be required to design shipping containers with hydrostatic flooding valves and enough ballast to ensure they sink promptly, but what is the likelyhood of our miniscule sailing lobby of ever getting that to happen?