For the complete picture: with a pole it's easier to set the auxiliary lines below the hulls!
I use even two help-lines:

One set to the middle of the beam-height running from front to aft (for keeping the pole swing-free straight out). And one line running from front to aft, attached just below the uppper hull.
Holding this line, I use it for keeping my balance when standing on the end of the pole.

The pole itself is fixed to the end of a traditional uphaul line over the upperhull (That was the easiest mounting).

I,ve said it before in this thread: please go out with a bundle of rope and try it on your cat in the water or on the beach

ronald