Yes, it most probably will work. St. Vincent and the Grenadines feature 2 cellular networks: Lime/Flow, and Digicel. Both are GSM. Both companies provide GPRS service. To be 100% sure please contact your mobile service provider, ask if you have roaming in your plan. Roaming charges can add up for data. Alternatively, if you have an unlocked/dual sim phone you can purchase a local prepaid SIM card, and buy a plan, 1GB data for example is only $15 USD. Wifi is available in most hotels/bars/restaurants and even some of the yachts.There are great talk anywhere plans available, where you just pay about $15 for 200 minutes calling UK, USA or Canada.