rudder trouble

[Ancient Geek]

I'll just say again sharpen the leading edge where it breaks water.
Had the problem in a Merlin in the 1960's a rounded leading edge to the rudder sharpened and cured the problem.
In my brief foray into FD's in the early 70's we initially had a rudder with a very rounded leading edge and the rooster tail was spectacular, a change to a standard Hoare rudder cured the problem, so as our little meercat friend says......