If you have 2 weeks to spend in Caribe, you have to choose by attention places to stay for the night and places to have fun with beautiful sea, to optimize your journey and sailing.
First of all I suggest to organize a one-way trip. In this way you can sail with the right wind and you don't must come back with front wind, that should be strong.
Martinica is perfect for beginning a sailing holiday in Grenadines because it is a french territory, very similar to our condition and it is very close to the best islands in this area.
In particular Le Marin is a good port where to take your boat or catamaran. Here you'll find all you need, like food, spare parts, informations and so on.
What you'll read below is a schematic route that you can follow to have a great cruise in this area. For each step I'll give you some basilar information like distance (NM), route, sea condition and so on.
LE MARIN > MARIGOT BAY (St. Lucia) - 32 NM - big waves between islands
MARIGOT BAY (St. Lucia) > CUMBERLAND BAY (St. Vincent) - 30 NM - big waves between islands
CUMBERLAND BAY (St. Vincent) > BEQUIA - 18 NM - a lot of boats in the bay. buoys by rent
BEQUIA > MUSTIQUE - 12 NM - buoys very expensive, this is vip's island.
MUSTIQUE > MAYREAU - 20 NM - perfect wind
MAYREAU > UNION - 14 NM - good island for food storage and any other necessity
UNION > PETIT ST.VINCENT - 15 NM - private island with a luxury resort
PETIT ST.VINCENT > TOBAGO CAYS - 15 NM - the real paradise
TOBAGO CAYS - CANOUAN - 10 NM - strong wind in front
CANOUAN - ST.VINCENT (Blue Lagoon) - 30 NM