Port 8375

Deltas sent over tcp must be entirely on one line, and terminated by \r\n. (What happens if there is a solitary \n or \r in there?)

Seems to be it's preferred transport. Port as configured web interface, default 3000, maybe 80 / 443.

TCP port 10110.

It can use a SocketCAN adapter, e.g. CANable/candlelight as follows;

NMEA 2000 Source: Canbus (canboatjs)
Interface: can0

See also: CAN Interfaces

Recently OpenCPN has added SignalK support. It will connect to a SignalK server using the websockets protocol on (default) port 3000. You might still need to build from source to get a version that supports it.