Why the double hull tanker still useful?

Question

i hope anybody can help me to solve my problem

Answer 1

Safety...reduced Carrier Insurance costs, etc.

Answer 2

They have an extra layer of protection - the extra hull.  They are safer than single hull tankers - far less likely to cause a major oil spill.   You may find this link very helpful.

Answer 3

With a double hulled tanker, you are not as worried about punching a hole in the hull and spilling your product.

It's like having a hull within a hull.

Answer 4

Best to protect the waters when the drunken captain runs it on the rocks.

You rip the outer hull, but the inner hull will hold all the oil.