Embarking - Grog Walk

I am leaving in about a month on my second VV cruise. I have a 3:30 embarkation time, which is a little late but the best I could do. SOR is sold out. I could not get the grog walk first cruise and was super disappointed. What are the chances I will be able to get in the grog walk this time boarding at 3:30? And are there any tips to ensure I get to do it?