[D-fendr]

The other problem with it remaining under the surface is it isn’t caught by booms protecting the shoreline.

[Wonder Warthog]

"The other problem with it remaining under the surface is it isn’t caught by booms protecting the shoreline."

Uh, the further under the surface it is, the further away from shore it is. To get onto the beaches, it has to come up to the surface. The oil booms are deployed right along the water/shore interface.