hI, I use a Humpalumpa sea fishing trolly when fishing the dirty wall area, it is designed to carry up to 75kg, But it is loaded up with all the fishing tackle including tackle bag, rod bag complete with rest, beach buddy, food, drink, cooking stove, wind break etc, etc.
With all this gear plus the wife I would fish around a couple or three hundred past the breakers.
I am not sure that this would be suitable for the distance covered when fishing the distance some of you guys travel up the wall, unless perhaps with two persons gear when travelling light and pulled by both.