I think the dive shop names are confusing. There are many buy the same name.
We just saw two Bull sharks on my dive yesterday. Mario's cabo pulmo divers was the first shop in Cabo Pulmo. His son David is great at finding bull sharks. Find him to find the sharks. They are great to see.
I also have to mention that Mario was kind enough to drop me to the airport in his car. I had no idea how to get back to the airport from Cabo Pulmo and was afraid of missing my flight back to India via LAX. I also speak very little Spanish.
Mario and David, made it really easy for me. Find them... They dont have a website yet..