Altimeter

Gliders are generally more efficient in deeper waters. This is because they spend less percentage of the dive for pumping and surface communication. There are two major methods used for avoiding hitting the bottom. One is replying on a digitized bathymetry map of the area and the other is the use of an altimeter. Seaglider uses a combination of these two while Slocum relies only on altimeter readings.

Seaglider uses a 12KHz Applied Acoustics altimeter/transponder combo which can also be used to locate the glider using a topside unit.

While Slocum uses a 170KHz Airmar altimeter unit.

Implementation in Tuba

The BlueRobotics altimeter seem to be a perfect fit for our purposes here.