I'm trying to get my head around radio wave propagation in conductive media such as water, saturated rock, etc. What I know is that propagation is poor but better at lower frequencies and this has something to do with "skin depth". I have read what I can on skin depth but I struggle to relate it to a bulk medium such as a body of water. Is there a simple explanation of why conductive media are poor transmitters of radio energy? After all we use conductors to carry RF. Is it because a radio essentially detects the signal difference between two points (antenna and ground for example) and in a body of water the signal just bleeds away to ground?