Trailer launching is easier than trailer recovery as the boat must be positioned well on the trailer ,keel, hull placment etc. The previous owner of my cal used this method and used the long tongue so well described.
A flag similar to those used by dune buggy guys, attached to the trailer fender indicate the position of the keel support. I would consider going into the water to be sure the boat is ok on the trailer before pull out.
Also remember that most of the weight should be supported by the keel. I have seen unsupporetd keels loosened and damaged when there was space between the keel bulb and the trailer. In other words don't let the trailer hull supports take most of the load.
I use a hoist and lifting plates, for me it is alot safer. My marina and YC provide this for no extea charge. HAVE FUN, Mike