[chrisser]

I was thinking the same thing.

And is that floating assembly on the water around it some sort of oil containment device?

[Manly Warrior]

Certainly. I am sure that is not an anti-intrusion/swimmer net or anything that might prevent underwater access to the vessels hull, nah. Just an oil containment system.

[Corky Boyd]

It is designed to keep hostile scuba divers from planting limpet mines to the hull.