sdi certs more people than all the other (than padi )agencies combined , padi is the MOST expensive and a crossovers (all crossovers are pretty much the same , remember you ARE already an instructor ) can be done by my facility (don't get me wrong padi is a great agency , the biggest ) if you want expensive do the padi .............youll be surprised at your final bill (crunch all the numbers ill be around a third the cost if I except you i have to interview you as with me its NOT ABOUT THE MONEY )....plus my course is ONE ON ONE PRIVATE ....no one absolutely no one will be able to compete with my facility ..plus take out the air fare right away ...............but to each his own just trying to help you out .............steve