Someone sets the right Thrust in your airboat ?

Sorry man, I don't understand your question. Explain in detail what you are look for.

In most of the aeromodelos you have the inclination of the motor for the right to compensate for the sense of the rotation of the motor.
I read what the aquacraft also adjusts the motor for the right in 3 °, and he would like knowing if the airboat with the rudder out of the water it has the problem not to walk in straight line without using the right thrust.

look for page 7/15 http://manuals.hobbico.com/aqu/aqub2...anual-v1_1.pdf

This is called the AOA (Angle of attack) each boat is different so this is something that you have to play with to get it right,

As stated (in most aeromodels).... This does not cover all but it can be a good starting point. But since we are boats and not airplane I would suggest starting a ZERO. See how the boat handles and if not happy adjust until happy.

My problem is the rudder out of the water, since with the rudder inside the water the boat walks in straight line, and when I put it out of the water he has a tendency to slip, and makes difficult doing curved in one of the sides.

Different from the manual of the aquacraft, the airboat has a good performance with the rudder inside the water without "right thrust" (0°),but the wish to sail with rudder out of the water is because of the detritus.An example they are the bags of plastic

i have the aquacraft alligator. mine slides sideways just because there are like only 2 strips on the bottom that are ment to keep it going straight but dont. and the fact thats its a flat hull also..

i dont know if rudders would help

pics my boat
I think if it is not better to use two rudders out of the water

Carlosam, you need to decide if you want your boat to run on land and water or just water. If you use water rudders you will get better control, but you will not be able to run it on land. As for engine angle try to set the engine level with the waterline and straight with the centerline of the boat. Most of the time instead of using different angle offsets I just use a little trim in the rudder to compensate for running in a straight line. To set the hull angle you will have to shim the front or back of the engine to get the hull to ride like you want it to. Dennis

And you wont be able to run through water that is laden with weeds and Lilly pads.

It is, therefore, that I think about the use with the rudder out of the water.
I am thinking about the use of two rudders instead of one. Will there be improvement with two rudders?

Yes. The vast majority of the r/c airboats are dual rudder and I have never seen a full size airboat with just one rudder. Two will definately give you better control. Dennis

There are full size airboats with single rudders. You don't see many of them, but the are out there. The single rudders will be a little bit longer than dual rudders to get it in the prop wash. With the weight of full size boats, dual rudders are the better choice. In my years of building rc's, I have found that single rudders are more effective on the rc boats compared to full size boats. I have built many boats with single rudders that performed superbly, with enough prop wash deflection to literally do "water-nuts" (do-nuts) in a very tight radius.