Fat Rat1, A jetovator, or any vertical jet nozzle controler, allows you to adjust the jet thrust up or down in an effort to "dial in" the plane of the boat. As the conditions, load, swell, wind directions, etc., change, you can adjust (trim) the boat for max speed, max control, or just plain max "showin' off". You might say that a jet O vator is simular to cav plates on a flat. They're quite pricy, but people that have them swear by them. I don't have one, but if one were to come my way at the right price I'd jump on it in a minute.........Hope this helps you.. Moneypitt