Tabs on Centreboards

[beachedblastit]

Whilst I have read alot on the site regarding winged Rudder blades in the recent past and debate and information is still going on, I have not seen anything on tabbed/flapped centre boards and I would like to.
I find this aspect of development fascinating, probably becuase I can under stand the thoery better, so can any body answer the following questions;
1. Are the flaps/tabs on the leading edge or the trailing edge? which is best?
2. How are the tabs/flaps adjusted? and is the adjustment manual or automatic?
3. Is the mechanism complicated/?expensive
3. Does the change in hydrodynamic profile of the board that the flaps create have any significant effect?
4. Is retro fit a feasible proposition?
Please help me to under stand this better.
Thanks Nigel Reece

[samlaw]

I think, in far too simplistic terms.

1 and 4. Just change the trailing edge of your centreboard into an Aileron. Saw it out the section and put it back on hinged.

2. Some form of control mechanism is need set the position of the Aileron.

3. Assuming a good job is done, in the neutral position the profile would be the same as if unaltered.