Figure 8 loops? I think that also would introduce twist in the line, but two kinks running opposite each other so when you unfold the line it evens out.
If you want to store a line without twisting it, which cause all kind of trouble if you dont "unroll" the line, you should "fold" the line. In rock climbing 60 meter ropes are used, and to stop kinks from forming they are always folded when carried or stored.
If you look here, you get the idea, just scale the folds down to fit your length of line.
http://www.swcp.com/~nmmc/climbrocks/knots/butterfly_coil.GIFWashing the line every fall when putting the boat in storage is a really good tip! Makes it last longer and it is nicer to handle afterwards.
