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. .. image:: /images/SeagliderAltimeter.png :alt: Seaglider components While Slocum uses a 170KHz `Airmar altimeter unit `_. .. image:: /images/SlocumAltimeter.png :alt: Slocum glider components Implementation in Tuba ----------------------- The `BlueRobotics altimeter `_ seem to be a perfect fit for our purposes here.