"Do you think this concept is being placed on an ocean platform because of the limited choice of equatorial land locations? The lease would be cheaper too, I guess."
Try to think of one equitorial land location where you'd be assured that security could be maintained. I tried and couldn't do it. The equator runs through some of the worst hellholes on earth.Having its achor platform in the Pacific on what would be analagous to a semi-submersible drilling rig would provide for an excellent security perimeter as well as having the ability to move it if you needed to.
Imagine being the guy tasked with calculating the dynamics of moving a ribbon 30,000 miles long!
Here's where Coriolus math comes in handy.