I have sailed St. Martin five times total over the years. The area, in my opinion, is good for about seven days at most. I have done the St. Martin to
BVI passage twice and found it can be done in daylight hours if you happen to be on a relatively fast
catamaran. On a slow boat, you may need to plan an overnight
cruise to arrive to make safe landfall in daylight.
My
advice is, if weather permits,
head to the
BVI as soon as you get the boat ready for departure. Then, go to the BVI and clear in at Spanish town. Sail the BVI for about 2 1/2 weeks, then plan on returning to St. Martin. If the weather is bad on the day you plan on returning, stay in the BVI, and don't leave until you have a good window. If you give yourself a week and a half to get back, you should be able to get decent passage conditions for at least one day and night.
If you haven't been sailing in the BVI, you will find the area has plenty of
anchorages with things to do, restaurants, and bars. The
navigation is easy and involves only line of sight and coastal piloting skills. The hazards and
reefs and clearly charted. You should have fun.
Summer sailing in that part of the world though can be hot, at times with light winds, and of course, at times possible storms. Just keep an eye on weather. Weather information in the BVI can usually be picked up on NOAA Channel six, on
commercial radio, and if you have a
laptop, via wireless at several locations with hotspots.