The rudder actuators (fins) don't have ROS integration support in stonefish_ros2. Please add that for AUVs with fins actuators.

[JustA3DObject]

Looking at the ROS integration documentation, it only provides automatic topic creation for:

Servos (joint actuators)
Thrusters (link actuators)

Rudders are not mentioned in the ROS integration documentation, even though they're defined in the core Stonefish library.
I have an XML file with <ros_subscriber> tags for both thrusters and rudders, but only the thruster topics are created.