You're pretty much right. But they have a special rope that they hold behind their butt. That way all of the pulling is done with thier legs, not the arms. I have an old ski race boat and I think they are one of the best set-ups for every day lake us. They can run hard in the roughest water as the boats are thick and heavy. Mine has two 40 gal gas tanks so it can go for the long haul too. My boat is just about like this one but has had a back seat added.
http://wsphotofews.excite.com/004/JH/d1/Jj/lF97285.jpg
Here are a couple more ski race boats. Look close and you can see about 4 other ropes in between the 2 boats. The black boat is driven by the owner of Schiada Boats.
http://wsphotofews.excite.com/004/6B/RB/gj/lu23317.jpg
Here is a skier holding the rope wrapped Aussi style.
http://www.topshot-topgun.com/GRAPHICS/LEA.JPG
Now just when you think it does not get any sicker than that. The grand daddy ski race is the Long Beach to Catalina Island and back. It is 62 miles in open ocean and this years winning time was 51 min and some change! The fast guys (and gals) are being pulled behind big offshore boats!