-- Last Updated: Nov-25-12 8:49 AM EST --
as the other who have posted - at least in the kayaking realm. But personally I found that the Zephyr is significantly more lively and maneuverable than the Tsunami - by a LOT. So for river paddling it is a huge improvement over the Tsunami and boats like the Tsunami. Also, I find that it is reasonably fast and with a touch of skeg it tracks similarly to the Tsunami. So in my opinion for many folks it will meet their needs extremely well. Keep in mind, I'm no expert, not even close. But I do appreciate and enjoy the maneuverability of the Zephyr in moving water.
EDIT - I see you are talking about open water and I should say that I do a lot of open water paddling as well and the Zephyr does very nicely in rough and close conditions. Whether it is among the best available hulls for salt water rock gardening I have no clue - but I do know several folks that use it for exactly that sort of padding all the time and love it.