It almost looks like a fake mock-up.
If they can sail it, those rigs are going to overlap a
LOT and the front guy looks like he would be quite cramped. Not to mention it must be bugger to get started....

Water starting our tandem speed board is really hard with larger sails (5.8m and up) because of the overlap, and it is 10'8" long (325cm). If I was designing a new speed tandem I would not go much, if any shorter than 300-315, maybe a bit wider, but I think I would put a significant step in the tail.