Jocho,
I read in another thread you are coming into my trade. Here is a first hand account of things which will answer your particular posted question:
From the day you are sworn in, you are a mat3(OS) until exactly 30 months from the day you begin basic training. On that day, you will be eligible, no questions asked, to become a mat2(AB). Whether you are promoted on time remains to be seen. Your QL4 OJT package completion will have no bearing on your rank or pay. Then, you will be eligible at 48 months from that same day (basic) to be promoted to mat1(LS). I should add, that if you are good at your job, you MAY get the opportunity to be advanced-promoted up to six months early. Roughly about that time you will be taking your QL5A course. Upon completion of that course, you will be Specialist 1 qualified. Here is where you will also get a nice bonus ontop of the largest single increase in pay you get, your pay jump from AB to LS.
the Sonar Op trade does not qualify for spec 2 incentives in pay.
WRT deployments, perfect example. Two years ago, two guys were completing their QL3 course and both posted to my ship. We left on a deployment before one of them could even get to Halifax, due to him sorting out some of his personal business. He was flown across the Atlantic to meet us at an early port visit. He had a six month deployment under his belt before he ever experienced living in halifax/securing living accomodations/experiencing life alongside in his home port.