Periwinkle, the TR-1 comes as a basic system with all the bells and whistles built in. If you don't want to use GPS just don't interface and it's not there. I have used their system since they first came out about six years ago. I don't use the GPS feature but live with the remote steering and throttle. The biggest problem I've had with them is reminding myself to pay attention to boats in front of me. They have really improved the system from when they first came out. You buy one and you will never regret it.