There are a lot of elements thatresult in failure to get up. The rope is never one of them.
Most people try to stadn up to soon. Even these big boats need some time to develop horsepower.
Often I see people think they are not getting enough power so they ask for more power and that can be a problem.
Many inexperienced drivers think they need to get you up to speed right away or you will be angry so they rush the throttle.
I have found that training them to watch the tach rather than the speedometer works pretty good. Never rev the tach past where you would normally ski. Instead a steady increase in power up to about 3000 RPM is usually good. If you have speed control like Perfect Pass a steady increase to about 12-18 mph is usually enough and then the PP will kick in and finish.
One other trick that has worked for some (especially if you start on one foot) - do not sit in the water all balled up trying to maintain that perfect starting position while the rope feeds out and the driver gets ready. Float comfortably with your feet well out in front and as the boat starts to pull allow your body to compress into the starting position. This may prevent you from trying to stand too soon and allow the boat to develope some horsepower.

Remember - you can get out of the water in a very squatted position if you want - but you can not if you bury the tip.

You do not need a 10 section rope. Unless you have some crazy good skiers you hang with. Having said that - I have one and love tinkering with short line - but my coach hates it when I do.

Good luck - and avoid skiing on the tower - most boats are not really designed to handle slalom from the tower.

Have Fun