thank you Sir.. now i am taking some self research, about propulsion, as i am not willing to use a flexible drive shaft.. so, trying with natural angled prop shaft, with hand made props.. in either directions.. and just checked at morn, in lake, and i was astonished with it's mode of running.. the power is too excess.. cant open throttle even slightly.. so, i am rewinding again the used motor for lower specs.. and thanks again for the advice, that can use rudder straight under the prop wash, and you are true, at first i was using a 9 grm micro servo, with a two inch valanced rudder plate, instantly ripped off from its mounting.. and the gears of servo was grinded.. so, after that i turn to a indirect drive servo, heavy, from Futaba from my older collections.. now working nicely.. i placed the rudder just behind the transom, with reinforced steel wires.. still waiting for the re trial, with reworked motor.. waiting to dry the insulation varnish.. and will also try with minimum ESC timing.. hope works.. once again, a million thanks for the advice and the great photograph.. will be back with crafts..