uuv model is falling straight through the gazebo world

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I am creating a uuv in gazebo trying to go through the project dave tutorial: https://field-robotics-lab.github.io/...

However, though I have input my mass and inertial values from solid works my uuv appears when I launch gazebo and falls straight through the world.

This is my xacro file below.

<?xml version="1.0"?>

<robot name="test" xmlns:xacro="http://www.ros.org/wiki/xacro" >

  <xacro:arg name="debug" default="0"/>
  <xacro:arg name="namespace" default="test"/>

<!-- "Dummy" base link to eliminate root link inertia warning -->
<link name="$(arg namespace)/base_link"/>

<link name="$(arg namespace)/test_link">
    <inertial>
        <origin xyz="0 0 0" rpy="0 0 0"/>
        <mass value="34.622"/>
        <inertia
            ixx="47.76" ixy="0.0" ixz="0.0"
            iyy="47.73" iyz="0.14"
            izz="0.12"/>
    </inertial>
    <visual>
        <origin xyz="0 0 -0.9" rpy="0 0 1.5708"/>
        <geometry>
        <mesh filename="file://$(find test_description)/meshes/iver3_wedge_mast.dae" scale="0.02 0.02 0.02"/>
        </geometry>
    </visual>
    </link>
    <collision>
        <origin xyz="0 0 -0.9" rpy="0 0 1.5708"/>
        <geometry>
        <mesh filename="file://$(find test_description)/meshes/iver3_wedge_mast.dae" scale="0.02 0.02 0.02"/>
        </geometry>
    </collision>



  <!-- Attach test_link to the dummy base link -->
  <joint name="$(arg namespace)/test_base_joint" type="fixed">
    <origin xyz="0 0 0" rpy="0 0 0"/>  <!-- X-fwd, Y-lft, Z-up (ick!) -->
    <parent link="$(arg namespace)/base_link"/>
    <child link="$(arg namespace)/test_link"/>
  </joint>


 <!-- Default joint state publisher -->
 <gazebo>
   <plugin name="uuv_joint_state_publisher" filename="libuuv_joint_state_publisher.so">
     <robotNamespace>$(arg namespace)</robotNamespace>
     <updateRate>50</updateRate>
   </plugin>
 </gazebo>

 <gazebo>
   <plugin name="gazebo_ros_control" filename="libgazebo_ros_control.so">
     <robotNamespace>/$(arg namespace)</robotNamespace>
     <robotParam>/$(arg namespace)/test</robotParam>
   </plugin>
 </gazebo>



</robot>

I can't figure out whats going on. Any help would be appreciated!