You may be able to find a tour that will take you, but more than likely your best bet is to rent a car and drive. When up there I saw a couple vans with groups, but most people were in their own cars.I'm sure you can rent from the cruise port and getting around is quite easy because there is just one road that rings the lobe of that side of the island.

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Basse Terre, the island, is far too large to explore in one day. It has a multitude of beaches, hiking trails, waterfalls(with swimming), and the volcano hike. Basse Terre, the city, is small, beautiful and on the west coast. We did not hire a guide. We went to the tourist information in St Claude. They spoke English and were very helpful . We picked up some maps and brochures. Everything we did, we planned ourselves. I think any of the larger towns will have places to get information, and everyone on the island is super friendly and helpful. As for the best way to get around, you definitely need a car. To see as much as possible, you need to do some advanced planning. Oh, give yourselves a bit of extra time, as some of the road signs are not the best, like signs for the National Park.