try up around Potiki Bay, how long is your rope chachi?
a good idea is to put a small net float or a small bit of polystyrene taped on about 3mts up from the pot this will stop it getting in the road of crayfish entering plus keep it out of the rocks/weeds,
then add a weight below the float 4/5mts down, to make sure the rope sinks and is not run over by other boats plus it makes it harder to see,
make sure the crays can not get to the food from the outside,
try and make sure it sinks even when throwing it over the side,
try to put it on a flat bottom but not more than 2/6mts away from a crack which might hold crays...
Thanks for everything you did for us Eric. may you rest in peace, You were one of the real legends of NZ recreational fishing