On Saturdays there is a 7AM ferry from Charlestown which will get you to dock in Basseterre shortly before 8AM. From there it's about a 12 minute taxi ride to the airport. If you are comfortable getting to the airport around 8:15AM for your 9:30 flight then take the ferry. This is a good option if you are able to check-in for your flight and print out your boarding passes online and you only have carry on luggage. Otherwise you are cutting it a bit close. NOTE: If you are flying on American Airlines you should know they require all checked luggage to be ":checked in" at least 1 hour prior to scheduled departure.
Islander Watersports has a "scheduled" water taxi that leaves Oualie Beach at 6:30AM on Saturdays. They will arrange for a land taxi to take you to the airport. On average, if you take this option you'll arrive at the airport by about 7:15AM. This is the best option if you or others in your party are unable to check in online and/or you have checked luggage. You should "call ahead" to let them know how many people are in your party and so they can arrange for the proper size boat and number of land taxis to accommodate your group and others who may be going at the same time.
Of course, you can also arrange for a private water taxi for just your group. Either way, you'll find contact info for the water taxi here: https:/…
Thank you for the info. We will do the water taxi.