Susan: Wow, that Real Estate Agent is spot on! I think it would be terrible to purchase someplace just to realize in a few months that it wasn't the right location for you.
There are a number of Florida cities with cruise ports; the ones I can think of off the top of my head are: Brevard County (central east coast), Broward Miami/Dade Counties (southeast coast) and Hillsborough County (Tampa Bay area central west coast.)
I think you should do as the realtor suggested and rent for six months to even a year or more; take your time visiting different areas of the state to see which feels most comfortable to you. You might even consider leasing a motor home if you prefer that style of living and take your time traveling around Florida to find a city to your liking for your forever home. :)
Also ... when the time comes, ask questions of folks here about the city you plan on moving to; I'm sure members would be willing to give recommendations on possible rentals or at least what area of the city would be good/bad regarding crime etc.
