Weed is not legal to buy on St. Croix without a medical card. Cannabis has been decriminalized and is a small fine for the possession of up to an ounce. Check out this article to find out more if weed is legal in the virgin islands
You must go to the Office for Cannabis regulations to obtain a medical marijuana card on St. Croix. You will need to provide ID and a not from your doctor recommended medical weed. For more information on obtaining your medical card see this guide.
Smoking wee in public is illegal on St. Croix even with a medical marijuana card. While many people do openly smoke weed in public at night, it is still against to law.