Well we just ran it through an oscilloscope and we are only values of -1 or 3 volts.
The depth sensor in question is a Garmin Intelliducer Thru Hull NMEA 0183.
We were able to get the GPS information earlier. but thats because of the many guides online.
Unfortunately the Depth sounder is not working in our favor.
We are powering it using a DC power supply.
The only pins connecting to the arduino is the ground and the signal pin