One thing more. I use a simple system to tack easily, but I don't know if it works only whith the straight and higher rails (especially on the bow) of MKII or also with the more rounded MKI ones.
The system is to always think that Serenity works sometime in the opposite way compared to a common board, so after passing on the other side of the board you can push with your HEELS to submerge the curved windward rail when starting moving and so the board will turn DOWNwind, instead upwind like all other boards. I use this system also whan jibing and in every other situation I need to turn almost quickly. It's using the feet for turning like on a planning board, but... in the opposite way! A brain exercise togheter with the physical one of windsurfing, imho.
Imho again and sorry for my bad english