My simple math on algae production

The USA consumes 800 million gallons of oil a day. A well managed acre of algae per day can produce 200 gallons, and that number should rise with technology. That is .13 million gallons per square mile. I have farmed 640 acres before, I should put that on my resume. 640 acres is a square mile. Who is going to farm a square mile of plastic floating bags? A stationary supertanker might.

So, do I have that right? .13 million gallons per day per square mile of algae? 5000 square miles of algae farming off shore in the Caribbean. Do a lot of it on shore, get algae production up to 200,000 gallons per acre per year. Easy stuff.