How to get around on land with a baby

[bangzoom6877]

I am cruising on the Norwegian Spirit in April 2006, on a 10-night sailing from NY to 5 different islands in the Caribbean. We're going to St. Thomas, Tortola, Antigua, St. Maarten and Barbados. We are definitely not bringing the baby's carseat (he will be 15 months old when we cruise). We will have an umbrella stroller with us. How can we get around on the islands? Is there public transportation? When I went to Bermuda when I was a teenager, in 1991, there was a public bus that took us to the beach and other nice areas, and it was reliable. I would have no problem taking him on a public bus or ferry, as long as they allow it of course. Is there reliable transportation in any of these places? We want to keep cost to a minimum, so we wanna try and avoid shore excursions. Plus, I don't think he will want to sit for 3 or 4 hours for an excursion. I feel it just wouldn't be enjoyable for him. But I thought going to the beach for a little while and maybe walking around would be nice. Any suggestions? (I don't wanna have to buy any expensive equipment either, like that combo stroller/carseat for $200).