1.  See if you have an adequate load path (considering direct support first).
2.  If not, can you supplement and correct.
3.  If not, don't do it.

Look for a spot in the basement - where it will probably end up...

Can be done as Ron says - get someone who is familiar with this type of construction and loads to help you.

Thanks to Mike and Ron.  With no record drawings available the procedure will have to be to remove enough wall, ceiling and floor covering to find the load path to the foundation.  My next question is do either of you know of a contractor or engineer in the Tampa Bay area who has experience in this business?

Thank you.

You need a contractor to do the demo for destructive observation, then you can observe for load path.  I don't know a contractor who does this in the Tampa area, but R.L. Haines out of Orlando has done similar for us and they work all over.  Check with a couple of the local structurals for a recommendation on a residential structural engineer if you need one.  They usually don't stray far from home, so better to get one there if you don't feel comfortable with it.

Firm up with the client what the type and size of the hot tub is prior to designing and ensure that this is clearly stated on your documents.

This is usually a case of where it can be put rather than where they want to put it.

If there is a corner with good solid walls and a poor floor then it is possible to mount the hot top on a triangular plinth with a beam across the front diagonally spanning between the walls.

as others have mentioned, understanding the existing structure is key.