Fathom theter and Fathom x- thether

Blue Robotics Products Tether Interfaces
1

While ago, I have bought 100 meters of the following cable:

Nowadays, i am design an underwater vehicle (that will receive data and power via that same cable). In sum the cable will plug into a pcb via micro-fit connector, where later it’s redirected into the fathom-x board, via another equal connector.
To guarantee that the signal reaches the vehicle with a similar properties that leaves the surface, i am trying to use some impedance matching. Therefore i need to know the properties of that cable or at least it’s impedance per length, the link refers 120 ohms @ 1 MHz and doesn’t specified the associated length, so could you please give that specifications?

Much appreciated and Best regards,

2

PS: Some information that i forget to add above

Properties of the cable needed:
->Diameter of Wire:
->Seperation Between Wires:
->Substrate Dielectric:

(Maybe i could retrieve the first one from the AWG rating?)