Don't know from experience but I saw a (youtube) video of a big man solo-righting a Nacra 5.5. He was sailing with what may have been his (early teens?) daughter. The wind was light and the boat came up in seconds with no help from her (she was sitting on the lower hull at the forward beam, not leaning out).

There are guys on this forum who sail a Nacra 5.2 solo, that's 17feet. But the lighter ones at least seem to have trouble righting one solo. I own a 5.2 but have yet to test solo righting.

Guess this doesn't help you much, but at least I bumped your post!

[edited for spelling]