Anyone tried a in-water rudder for an air boat?

Looking for pros, cons and efficiency with respect to different cruising speeds of such a steering setup.

Water rudder will cause a lot of drag and will reduce the speed considerably. Otherwise maneuvering should be ok.

Shreekant

Airboats are primarily designed for use in shallow water. If you do have an underwater rudder, you have to forego that advantage.

Quote from: VC on July 02, 2013, 06:22:11 PM
Airboats are primarily designed for use in shallow water. If you do have an underwater rudder, you have to forego that advantage.

with considerably sufficient depth for the rudder to operate in, it should be fine right? correct me if i am wrong.

Pros: Does not need to be on power for taking turns. That is, in a conventional airboat, the effectiveness of the rudder is directly dependent on the air flowing over it. Having a small water rudder will give you more yaw authority.

Cons: Your airboat will not move on land if you give it a water rudder.

The increased drag is negligible for a small rudder. I have both on my airboats, and they can do 360s on the spot

Quote from: lastRites on July 03, 2013, 12:25:27 AM
Pros: Does not need to be on power for taking turns. That is, in a conventional airboat, the effectiveness of the rudder is directly dependent on the air flowing over it. Having a small water rudder will give you more yaw authority.

Cons: Your airboat will not move on land if you give it a water rudder.

The increased drag is negligible for a small rudder. I have both on my airboats, and they can do 360s on the spot

that's what i was thinking too, i can extend the air rudder a few inches into the water and i can have a water rudder too; actually, two water rudders
I dont run the air boat on land anyway.

how bout putting  2 water rudders and hinging them, so they fold up when it hits a obstacle and falls back down while sailing??

Sent from a potato using a lamp

An inch underwater would be enough. Too much will increase drag. Make it as thin as possible.

Quote from: aniket210696 on July 03, 2013, 09:27:27 AM
how bout putting  2 water rudders and hinging them, so they fold up when it hits a obstacle and falls back down while sailing??

Sent from a potato using a lamp

I'm guessing, hinging the rudder like that, it will fold up due to water resistance itself at high speeds

Quote from: lastRites on July 03, 2013, 09:50:24 AM
An inch underwater would be enough. Too much will increase drag. Make it as thin as possible.

an inch under water? that's half as less as what I had in mind. i'm gonna try different sizes then.

Last night, i was thinking too far and layed out a CAD for a small rig to check the hydrodynamicity of my boat parts using high pressure water