What are the different types of Naval Officers in boot camp?

I'm going to a naval sea cadet boot camp this weekend. My CO told us that there are multiple types of officers and one of them you can not address as Sir (not petty officer, one of a higher rank) they have something else that you have to call them but I don't know what it is. Does any one have any idea as to what I'm talking about? And if anyone knows of more than one officer that has a specific salutation please let me know, thanks.