Ardupilot underwater drone attitude problem

Hi everyone,

I’m having a problem with Ardupilot on my underwater drone. The drone is working fine in dry land, but when it goes underwater, it starts behaving erratically.

The specific problems I’m having are:

  • The drone goes underwater when it tries to go to a destination in automatic mode, even though I’ve set the altitude to 0 and the “Do not require takeoff” option in QGroundControl.
  • The drone starts moving back and forth in a zigzag pattern on the surface of the water.
  • In guided mode, the drone goes to the destination, but even if the head of the drone is facing the destination, it starts turning after a while and moves towards the destination from behind or sometimes from the side.

I’ve tried the following things to fix the problem:

  • I’ve set the attitude offset to 0 in dry land.
  • I’ve increased the IMU filter rate.
  • I’ve disabled the GPS yaw output.

None of these things have worked.

I’m wondering if anyone has any other suggestions for how to fix this problem.

Thanks in advance for your help.