Autonomous robots can help people explore parts of the ocean that would be
hard or impossible to get to otherwise. The increase in the availability of
low-cost components has made it possible to innovate, design, and implement new
and innovative ideas for underwater robotics. Cost-effective and open solutions
that are available today can be used to replace expensive robot systems. The
prototype of an autonomous robot system that functions in brackish waterways in
settings such as fish hatcheries is presented in this research. The system has
low-cost ultrasonic sensors that use a SLAM algorithm to map and move through
the environment. When compared to previous studies that used Lidar sensors,
this system's configuration was chosen to keep costs down. A comparison is
shown between ultrasonic and lidar sensors, showing their respective pros and
cons