You may want to try SSI’s instructor rating. It is a tough course and the physical requirements are brutal if you are out of shape but doable. Also they emphasize the course work is tailored to the students needs and safety is paramount. They also sllow some leeway when it comes to going over the standard within reason. PADI and NAUI are very strict on being exactly on the standard and anything over the standard is a deviation as well. The students really learn easier with the SSI style and the SSI support is great for its instructors.