How to launch a boat from a trailer

Keen to take the stress out of slipway work? Boating instructor Jon Mendez shares his essential guide on how to launch a boat from a trailer...

For many of us, our introduction to boating would have been a small trailer-launched boat that we towed to the water whenever we fancied getting afloat. If it was a launching site that was unfamiliar, there was always that moment of trepidation when you first saw the slipway and discovered how usable (or unusable) it was.

Google Maps and Street View have helped remove some of that trepidation but you still need to carry out a basic survey before launching your boat. How steep is it? Is there a drop-off at the end? Is it clear or covered in weed and slime? Is there a fee to launch? Where do you park to get set up and what about the trailer after you’ve launched?

Having arrived, I like to park well away from the slipway while I get ready to launch a boat. My task list usually follows a pattern. Remove all the boat items from the car and place them in the boat. Turn the boat batteries on, check the trim is working, remove the trailer board and then tie the boat to the trailer on a bow line that I can release from on board.

Then remove all the tie-down straps, except the winch strap. Crucially, make sure that the stern bung is in place and that, if you have them, the stern drains or elephant trunk drains are up and secured.

The exact order of the boat launch depends on how steep the slipway is. But a key point is never to allow anyone to walk behind the boat and trailer, as that can be highly dangerous. In this instance, we used a trailer with launching wheels holding the boat's weight.

Article continues below…

We can only imagine how the owner in this boat fail video must have felt as they watched their new

In contrast to bunk-style trailers, that means you don't have to go too deep into the water to launch. Position the boat at the top of the slipway and trim the engine down slightly. Now gently drive backwards so that the trailer wheels are just at the water's edge.

I now release the winch strap so just the bow line is holding the boat's weight before climbing aboard. Now I ask the car driver to reverse 2m, so that the car wheels are just at the water's edge. I use a system of two fingers for 2m, one finger for 1m and a clenched fist for stop.

I can now lower the engine, just until the water intakes are covered. Go and have a look if you are at all unsure. But if it's deep enough, then start the engine and let it idle for a few moments while looking for the cooling tell-tale. Then lower it a touch further.

At this point, I go to the bow and release my bow line that was holding the boat onto the trailer. Now get back to the helm, make sure the wheel is straight, put the kill-cord on, and engage astern, just at tick-over to start with. Having the engine still trimmed up is helpful as it slightly lifts the stern off the trailer while also pulling backwards.

Depending on your trailer setup, you may need a few extra revs to get the boat moving astern, or you may need to drop the trailer deeper into the water. As soon as the boat starts moving off the trailer, drop the revs or even go into neutral to prevent things happening too quickly.

When off and clear, move to deeper water, fully trim down and, if practical, go and moor up so you can help park the trailer and collect the rest of your group.

First published in the June 2023 issue of MBY.