If you want beaches/hiking/kayaking/sailing I would recommend staying on STJ, it has all that and more.
If you only have 4 days, I highly recommend just one island. There is so much to do and see on both islands, I can not imagine actually enjoying myself if I was back and forth too many times in such a short trip.

One place and I would choose St. John. If there is any way in the world you could stay longer, I would strongly recommend you do that.

I would also agree with St John (no S on John)

Take a look at Coconut Coast Villas
Great location and I think 4 days is the minimum stay

Many places in STJ have a minimum stay requirement.

St John

Four days is rough. More than a tease and you will be trying to figure out the return before getting on the plane. If the budget can handle it you might want to look at Caneel if dates are fixed. If not, extend to 7 days and get a villa. Don't try to see everything in 4 days as it won't happen and you loose the experience of each place you visit by thinking abut the next one. Take a few in and enjoy them for what they have. Plan on the return knowing there is so much more to see and do.

Enjoy

I agree with you Chris

That is why I suggested Coconut Coast - it is within walking distance to Cruz Bay, Salomon, Honeymoon.

I figured day one you get there afternoon - hungry ready for a drink... walk into town

Day two walk to Honeymoon or Salomon

Day three maybe a dinghy a Little Noah's and hit the northside beaches

Day four - wish it would have been 7 days.... or more

No car - No rush to go anywhere - Just try to chill quickly

Kinda like one of those 15 minute power naps - great idea until the 15 minutes are up...

A good way to enjoy the snorkeling and waters surrounding the islands is by chartering a boat for the day. Try direct booking with the charter company and asking for 10% off.

see website
www.truecompanionvi.com