hey mate, it all depends on how old the boat is and if the trailer is a good one. Generally a boat over 16 feet long is a 2 person job. One to hold a bow rope and a stern rope from the jetty (if there is one) and one to let off the winch at the front.
when you are retreiving it, keep the person on the jetty with the bow and stern rope (this is usually one long piece of rope hooked to both) and push the boat away from the jetty so that the boat lines up, if they push too far, then get them to pull the lines till it is in line. then hook on the winch and wind away.
Its easier if you unwind your winch before you back the trailer into the water and put the hook on one of the back pulleys, out of the way of the wheels.
Good Luck,
Az

remember to put the bungs in the boat before you launch it. SERIOUSLY!

hmm....anymore advice?

one thing that you might wanna note, is it can be hard to see the trailer when you are reversing down to retreive the boat. makes reversing fairly tricky, as without the boat on board, some trailers are very hard to see (cause they are low) especially out the back of a 4wd.

i usually get a mate to stand on the trailer when i'm reversing... (probs not the safest thing to do) but i find it a lot easier to reverse trailers myself then to take directions off people "nah left a bit, nah i mean right.. and left more... yeah go straight".

Siaw,

You'll need to take a good look at the conditions and the area before launching, yes. Make sure your out on a calm day, always protect your boat from the jetty, make sure your vehicle is fit for the job. Take some time getting the boat lined up before and while your winching it up. And it pays to make sure your rollers are in good condition for smooth launching and retrieval.

Because the trailer is hard to see at top of ramp (trailer goes over before car) with you can put a polls on trailer to assist reversing. Otherwise don't turn the trailer when it goes over top of ramp and u have lost sight of it. Only reverse trailer in minimum water boat needs to launch, whilst most hubs and lights are now pretty well sealed it still does you're trailer no good giving it salt bath, plus ramps get slipperier the closer you reverse to water.

Pull up away from ramp at first, set everything up- put bungs in unhook safety chain if you wish, connect fuel to outboard and prime, do final check that all gear present and stowed away and if going out at night check all nav lights. You can run out bow rope carefully and tie it to onside at rear of trailer that way when pushing boat off it will stop and not pull you off feet on slippery ramps (just make sure it wont foul rollers or run under wheels when reversing).

Again when about to retrieve boat make sure winch cable run to rear of trailer. When boat on trailer disconnect bungs so any water will run out whilst boat on angle. You're aim is to spend as little time on the ramp as possible, if you doing by self wait till a spot at side of ramp becomes available so it is quicker to move boat. If you polite at ramps and even let others go first often people will help.

Finally take the time to set trailer rollers correct, often shops just do this very dodgy. At worst incorrectly set rollers can crack the hull (i've seen alloy boat cracked we suspect from bad roller set and a trip to the cape), at best they make launching and retrieving alot easier.

grumplestiltskin, Thanks for the advice, Someone experience will be driving the trailer. As to operate a dinghy...I have no idea how to steer the motor, but I believe the concept is the same,I'll proabably will have a go with tiny boat in Rockingham first. Anyway, I'm here to prevent disaster, any advice would be appreciated.