The NF-826 cable locator works great
Bought a NF-826 cable locator and it effortlessly pinpointed a power cable buried 60cm deep in the ground. You have to understand some basic physics to use this kind of tool and the user guide is fairly basic. In my case the cable was shielded (which is very common) and applying the trace signal to the neutral or live wire is useless since it is then within the shielding. Applying the trace signal to the ground/shielding of the cable did the trick and when i dug in the ground i hit the cable dead on. Very impressive.