My biggest question is how they plan on securing these ships. Pirates would likely see this as a huge opportunity.
"Pirates captured a Saudi-owned supertanker loaded with more than $100 million worth of crude oil off the coast of Kenya, seizing the largest ship ever hijacked"
http://www.nytimes.com/2008/11/18/world/africa/18pirates.htm...
Hell, you could go a step further and equip each one with it's own drone to defend itself in case of attack.
If it were so, wouldn't such systems be already installed on manned boats? There's nothing here that is tied to the boat's capability of self-steering.