I've adjusted the rudder line tension as you suggested (on a hot day).
They were quite tight, now there's afew mm more length in each side,
and they are not tight at all.
I also cleaned out the rudder pin housings and removed sand and noticed the PIN, which I replaced
for the later part of our last trip out, already has quite deep scuff markings
near the top - it's only been used for a couple of hours.
After cleaning, the rudder PIN moves quite freely in the housing, and even up and down a bit.
As for the rudder controls, I am still noticing some resistance when turning the front
control towards the cockpit, but not when I turn it back.
There are multiple "pinging"/"clicking" sounds, which sounds like lines coming under tension.
The sound seems to come from inside the hull, about a metre back from the front control.
This does not occur with the rear rudder control.
This is still concerning me, especially as I noticed great resistance to
turning the boat to windward, when at high speed, and high winds.
I have never used the rear control; I always sit in the front.
I also noticed a tiny black piece of tubing rolling around in the hull afew weeks/months
ago. Could this be important ? (see photo)http://members.iinet.net.au/~peterwalters/hobie1.jpg