Hi Noel, a Starlet or Star Baby will sail in less than 18 inches as will a large barge. But first of all what do the local club members sail?
My suggestion to a newcomer is generally the same. Get yourself a working yacht so that you can join in, Waiting to build a model especially a scratch built model will take time and may kill your interest. I suggest an Aeronaut Bella for a quick build. It comes complete just needs radio.
But to reiterate the above, chat with the sailing guys, see what they sail and perhaps ask if anyone wants to sell you a working one and learn how to run the radio and the boat, the other stuff is easy just specialised knowledge, but nothing difficult.
Good luck and welcome.
Roy