Doubts about gps positioning device on ship

Hello!
I want to learn if I can make an electric gps positioning device on board, which is similar to the propeller of ‘’ minn kota”. Because I only need gps positioning and automatic return function of water offset, it is too expensive to buy a propeller of minn kota, so I hope you can help me to find out what accessories are needed to make the project successful.
Thank you all!