quite some time ago we added the underwater drone HippoCampus to the PX4 firmware incl. sitl_gazebo support. Unfortunately, it is still based on the multicopter airframe.
I am currently working on making it finally independent from MC, especially by providing an independent underwater drone / boat airframe and building a proper attitude controller.
Before reaching out with a pull request for this feature and just updating the the old HippoCampus files, the corresponding sitl_gazebo module has to be adapted/added.
As these are two repositories I was wondering what is the best way to proceed?