Hey, @williangalvani
after some more searching I got to this page in the documentation. According to it
Ardusub supports the use of an altimeter or range measurement input. If the range measurement is downward facing (altimeter), then the altimeter will be used to assist depth hold. When the altimeter measurement is valid, depth hold mode will automatically begin following the altimeter measurement and hold a distance above the bottom, as opposed to a distance from the surface when the pressure sensor is used.
To be clear, does this mean that depth hold mode can be used to keep it a certain distance off the bottom? If this is the case, what is altitude hold mode?