I suggest you figure out what kind of boat you are looking for and run the numbers of STT vs. BVI. Chartering out of STT - which I believe really means CYOA - has lower costs for air travel but has higher fees imposed when you clear C&I in the BVI. Some people here will feel passionately that if you wish to be sailing in the BVI that's where you should start. My opinion is different since I enjoy the beaches and bays on St. John which you would probably not get to experience if you started in BVI. So find a boat you like on both the BVI and STT end and run the numbers then decide if the delta - whatever it might be - is that important to you. Then look at the other advantages/disadvantages to see if they have value for you. Some issues you might look at are: boat selection/cost including age and equipment, total transit time and cost, i.e., from your door step to sitting on the boat, cost selection and ease of provisions, sailing area, hassle/expense of checking in/out of US and/or BVI. June is a great time to be down there and I'm sure you will have a great experience.