The usual means he referred to is making and keeping eye contact. Sharks do not like eye contact and will, as a rule, abruptly turn away. The problems with rules are exceptions to rules. My experiences with sharks is that eye contact makes them leery and they will attempt to get in behind you, even if not being aggresive. Of course as a diver, I kind of think something with teeth trying to get in behind me is aggressive. This more often happens with sharks that are not accustomed to people, wild sharks, who are mostly curious. I am not offering a solution, just answering your question as to what the usual means referred to is, it is eye contact.What are the usual means of diversion that you are referring to?
Prayers for the diver lady who was bitten.