Finally! I can't tell you how many By-the-wind Sailors (Velella velella) I've looked at...and I had yet to find a right-handed Velella, until tonight (11 May 2016).
Velella is known to have two different morphologies. Left-handed Velella have the sail angled across the body from the upper left to the lower right. The majority of Velella observed in the Bodega Bay area are left-handed.
Right-handed Velella have the sail angled in the opposite direction, i.e., across the body from the upper right to the lower left. The Velella pictured above is right-handed.
For comparison, here's a more typical left-handed Velella (on the left) next to the less common right-handed Velella (on the right). Compare the angles of the sails:
There's been a long-standing question regarding the significance of having a left-handed or right-handed sail. And people have wondered whether the abundance of the two different forms is related to being in the northern vs. southern hemispheres, or in the eastern vs. western sides of an ocean. As far as I know, the significance of "handedness" in Velella has not been well studied and remains a mystery.
If you come across a right-handed Velella, I'd love to hear about it!