F.e. if it is a condo or a co-op, you have to read their by-laws and other documents.
You have to find out about the terms of the lease (in writing).
There are different ways of holding title also - fee simple or leasehold.
Sometimes returns are bigger on the properties that others ignore because they don't know much about this type of investment. I suggest to work with a good realtor and a good attorney.
Good luck with your search!
Beachfront Realty, Inc.