Noelle is correct. The last I knew Tropic, which is a great airline for people and my preference, will charge you for as many as 3 seats to fly a dog because they put the kennel on the rear seat and will not allow others on this seat. The problem is that you just do not know what Tropic will charge until the plane is ready to leave. If the plane has a lot of passengers then you will pay for 3 seats, if not and if you push it a little you will pay for one seat. You will not know until the last few minutes.
Take the ferry or better yet take Tropic Ferry which will pick you up at the airport and deliver you to the closest dock to where you are staying. This is the method I have used for the last 3 years. The ferry may be cheaper but they let you off at a dock down town and then your luggage, kennel and whatever have to move either to a taxi or to the coastal express dock which is nothing but a pain. One year, several ago I talked the ferry captain to bring me over to the Coastal dock but that is the exception and not the rule.
Good Luck the companionship is worth it. Today I was seperated from my wife and dog for a while because I had to attend to some business. I asked the guys where my wife and dog went. I told them I was worried and really missed my dog.
Only kidding for those of you who know my wife but a dog is man's best friend.