Dieter,
Great to see you get amongst them.
Longer traces are a big key to Blackfishing off the rocks. I have had the same experience as you with a guy suggesting a longer trace and that turned the day around, like it did with you.
I start with at 1M trace and will shorten if I am losing baits and not getting downs. Sometimes you have to vary the trace length depending on the tide throughout the session,
Well done,
Geoff