Re: Antigua anchorages and snorkeling spots
prevailing winds are from the east, often northeast in winter months. So, anchorages on the western side of the island, in the lee, will be generally less rolly. Not familiar with Valley Church Bay. We started and ended at Jolly Harbour, and spent our last night in the outer anchorage just north of the entrance channel, which was crowded but comfortable.
Barbuda is about 30 mile passage from Antigua. You don't see Barbuda till the last few miles. We took the advice of Chris Doyle's book and folks at Horizon, and anchored two nights off the beach on the west side of Barbuda, north of Palmetto point, which is the safest approach to the island (fewer reefs to navigate). It was comfortable in the anchorage, although they say it can get rolly in northerly swells, in which case you might choose to anchor over near Cocoa point.
As for the passage, it is "open ocean", so pretty decent swells and wind. Wait for a nice weather window. We had a beautiful romping reach over to Barbuda, and another fun sail on the way back. Absolutely make sure to arrive around midday for visualizing the reefs. Your charter company will give you a lot of information too. I would say that sailing Antigua/Barbuda requires a higher level of sailing experience than, say, the BVI. Hope this helps.