If storage space is at a premium, and you lack a bathtub, here's a solution. Simply purchase an inexpensive inflatable boat. They can be found on Amazon and eBay for less than $40 USD, in a range of sizes. Inflate the boat, place it on a table or workbench, and fill with water. The flexible sides will allow you to run the boat without fear of harming the finish. Having it on a table makes it easy to work with your boat's ballasting, test radio, propulsion, steering, etc. When done, bail or pump out the water, deflate the boat, and store it away until needed.