Not sure about this, it may have more about it than we think initialy .
But after the recent Alderney trip I have given it some thought and already discussed it with others.
when on the wrecks we had several occasions when the fishing started well then every drift got worse.
On one mark the first drift all four rods were in, then on subsequant drifts zero.
an adjacent boat also reported that his fishfinder was being blanked with interferance from mine every time we got close.
There may be more to this than we think,
I will see if the sounder can be turned off next time, although on a combi unit I will have to look into that.
I could drift with plotter alone but not without both.
Charlie