To do that will require a computer system. the Garmin series (72 and above) will recognize a NEMA data stream and have a depth feature that will read from a device that will communicate with it. I think, however, that only some computer based sensor can stream the correct data to the Garmin and I don't think the Garmin will record the data - only display it.

You can purchase small, in dash, waterproof depth units. I once considered making a device that would fit into a port cover with a batterpack underneat. They make depth sensors that will look through the hull (without drilling holes) too. Perhaps just having a depth display might help you?