The easiest solution to keep the tiller in place when anchored or drifting  
is to simply wrap the main sheet around it a couple of times. It will hold it 
up  and keep it in place all at the same time. At the dock I use a very 
expensive  devise called a bungee. I attach it to the rail, wrap it around the tiller 
and  then back to the other side of the rail. It only lasts a few years and 
then  requires replacement. 
 
Rummy