Caneel is the point to dink into Cruz Bay as FarCry indicates... it would be a really long and in December probably a very wet and hard ride!
As far as places to visit in St. John, after you finish your business and do a walk around to Cruz Bay, heading back to Waterlemon Cay is a good place to consider it has great snorkeling with almost an assured chance for an up close and personal encounter with a large sea turtle and it has nice reefs on the Eastern end. Hiking trails to ruins and even over to Coral Bay are great trips. If it is your first time to St. John you may want to consider looping back around the Southern side of the island and heading toward Lampshier Bay and snorkel and hike those trails then head around to Coral Bay for a looksee. Head to Waterlemon at that point and stay overnight then return to BVI either to West End or Jost Van Dyke. If you have not hiked the trails on Norman Island they are well worth it.
St. John is a very nice place that should not be missed after multi visits to BVI. One other location you may want to consider as an overnight stop or a lunch stop is St. James Island (Greater) and Christmas Cove. Great little spot for snorkeling and free anchorage. In most of USVI you will have to moor at the National Park Mooring fields. In December you will probably have a Bay Host come by your boat in the afternoon about 5 to pass out maps and other literature including your pay envelopes you will have to deliver to the pay stations, generally by dink... they can not accept payments but have lots of local info and are very nice people!
As far as places to visit in St. John, after you finish your business and do a walk around to Cruz Bay, heading back to Waterlemon Cay is a good place to consider it has great snorkeling with almost an assured chance for an up close and personal encounter with a large sea turtle and it has nice reefs on the Eastern end. Hiking trails to ruins and even over to Coral Bay are great trips. If it is your first time to St. John you may want to consider looping back around the Southern side of the island and heading toward Lampshier Bay and snorkel and hike those trails then head around to Coral Bay for a looksee. Head to Waterlemon at that point and stay overnight then return to BVI either to West End or Jost Van Dyke. If you have not hiked the trails on Norman Island they are well worth it.
St. John is a very nice place that should not be missed after multi visits to BVI. One other location you may want to consider as an overnight stop or a lunch stop is St. James Island (Greater) and Christmas Cove. Great little spot for snorkeling and free anchorage. In most of USVI you will have to moor at the National Park Mooring fields. In December you will probably have a Bay Host come by your boat in the afternoon about 5 to pass out maps and other literature including your pay envelopes you will have to deliver to the pay stations, generally by dink... they can not accept payments but have lots of local info and are very nice people!