Loading a boat onto a trailer in some situations is a tricky business. Add a strong crosswind or a current at the boat ramp and it can become nearly impossible and even dangerous. The answer is to mount guides on the sides of the trailer that align the boat while it is still in the water with the trailer as you begin loading it and that hold the boat in position over the trailer as you winch it onto the trailer.
Home Built or Pre-Fab
If you have a welder, cutting torches and metal bending tools, fabricate side guides from scratch. If metalworking isn’t possible, purchase prefabricated side-guides that bolt to the frame of your boat trailer. To attach the side-guides to the boat, use ordinary tools such as wrenches, screwdrivers and perhaps a power drill.
Side Bunks or Uprights
There are two basic models of trailer side-guides. One style, a fairly low-profile design, involves little more than the adding another trailer bunk on each side of the trailer: Attach a pair of brackets to the frame of the trailer and then fasten a carpet-covered board to the brackets. This style positions the bunk-boards along the sides of the boat and, at most ramps, they will be under water when you back the trailer down the ramp. They aid in centring the boat on the trailer when power loading, but don’t do much to keep the stern of the boat in place in wind or current when using the winch to load up the boat.
If a bobbing or moving stern is your concern, make or purchase upright guides, which fit very close to the back end of the trailer and extend higher than the sides of the boat. To determine how high they need to be, back the boat and trailer into the water at your favourite ramp as far as would be needed to load the boat, then measure from the top of the side of the boat to the trailer frame. Make sure the model you buy or construct is that long or a bit longer.
If desired, construct or purchase the upright models with rollers, although carpet-covered boards positioned vertically upright to protect the side of the boat work just fine, too.
Installing the Guides
A snug fit between the sides of the boat and the side-guides is best. With the boat perfectly centred on the trailer, leave a maximum of 3 inches between the boat and guide. To get the guides to fit this precisely, mount the guides while the boat is loaded on the trailer.
Mounting bolt-on guides poses few problems, but if you plan to weld the guides to the trailer, ensure that you protect the side of the boat from the heat and smoke from the welding process. Use a piece of sheet metal or even plywood between the boat and your welding points.