maybe an advantage - but it's a real boat that can do it's amazing things in real water.

It carries a special GPS system that (I forget the details) has some redundancy...I think two or three separate systems that have to agree within a given percentage to be ratified.

The windsurfer / sailboard guys and gals can most certainly make their test runs whenever they wish - as long as they can afford to have an official present for each attempt. I do believe Hydroptere (and other speed craft making runs) pay to have an official present to ratify the results.