I am assuming you are talking dive curve related to the snap weight. Such as standard depth of lets say feet back of a particular lure of a tail dancer. A rough estimate I use is with each 1/4 of weight I will gain an extra foot of depth roughly. So using your dive curve will roughly gain 4 ft of depth with each ounce of weight added. Now this gets tricky because you need to take into consideration your speed, the line diameter, and the current in the water at which your lure is at. Also where you place the weight. I place my snap weights a minimum of 20 ft in front of the lure and a maximum of 60 ft in front of the lure. There comes a point that line out in the curve will be at max depth no matter how much line you let out. When those deeper depths need to be achieved switch to dypsies and tadpoles which will allow you to stay deeper more consistently due to the lip of the weight pulling the lure down.