I'm ( obviously ) no rotary wing type, but I thought there were systems in place to avoid flying into pylon wires - hell, I might even manage it with dowsing rods !
It's usually a map with a blue line, but the problem is not all the wires are marked and of course, sometimes the aircraft can arrive at the point on the map slightly before the map reader.
There are IR and GPS linked systems out there, but I'm guessing wires are not normally a major hazard for ship based helos, so they are probably not a priority for fitting such systems given the MoD's current budget crisis for a sustainable rotary capability.