Again, I would recommend Craigslist as the majority of folks here already have a boat
On Craigslist you will find a group of people who are already looking for a place to live, rather than a bunch of sailors who will likely just dis on you for having a Searay and calling it a yacht.
We have a guy in our marina who rents his boat
out on Craigslist and he always seems to have a tenant.
Also you will probably have better luck if you include details like what the rent is and a specific location. That will save you and them having to ask and answer basic questions that should be included in any advertisement anyway.