I run radio tabs on my 45" monos and 73" catamarans and they work very well and can be hooked up to mixing. They are very effective and simple to use. I set mine up in mill time for the number of boats out there and the conditions at the time. They can be adjusted during the race but better done before the race actually starts.

Fixed tabs are great if you are running by yourself or if the wind doesn't pick up or if the wind doesn't change direction. Other than that, fixed tabs are a complete waste of time as water conditions continuously change during the course of a days running and fixed tabs require constant adjustment to suit the changing conditions. Hope that doesn't put anyones nose out, it's just my opinion.

The ultimate would be a variable strut/ arnesen drive which I am working on. You need to remember that your trying to control the up and down movement of the propeller which can be between 70 and 90mm in diameter spinning at between 15000 and 18000 rpm. Theres a lot of forces applied to the strut which I believe will require more than just mechanical linkages from a servo to be truly effective. The system I am currently designing will use a servo to operate a small diameter hydrulic ram to in turn operate a larger diameter ram at the arnesen on my large catamarans. Radio tabs are a lot simpler so I'm sure I will be using them for a while yet.

Cheers, Danny.