Just sharing some of my experiences, I also did a 4D3N advance course at B & J too. Great teaching from uncle grahame... Strict uncle..
4D3N, I would say its a slow & relax trip.I still have 1 day to spare for snorkeling.
I would advise you to read some notes before going to the island for your course,if you have got the notes.
Actually you can go there by your own.
I booked 5 stars coach to mersing,if i never remember wrongly the timing of the bus was 6.30am.Only 1 time slot.$45 bucks 2 ways
Reach there around 10am+ you can take the 11am or 12pm ferry to tioman.
You can ask from the dive centre the ferry timing,they will have the ferry departure & return timing 1 month ahead.