There are several styles of guide-ons available, but all serve the same general purpose - to help you center your boat on the trailer while loading by counteracting the effects of wind, waves, and current.

Springs and other related hardware are prone to rust and corrosion, since they are often submerged when on/off-loading your boat. Serious damage can and will occur upon failure of a spring (your boat's shock absorber), U-bolts, or other hardware.