Winches are designed to load and unload boats, not to hold boats in place on the trailer. A bad bump in the road may cause the winch to release. To prevent mishaps, use separate tie-downs and bow chain and hook rigged for the purpose.
When using hand winches, be sure to get secure footing and proper leverage — many accidents occur every year from handles that kick back.
To minimize shoulder and back strain, try an electric winch. These power your boat onto the trailer easily and leave you with a free hand to guide the boat.
Choose a winch that has a capacity rating of at least half the combined weight of your boat, motor, and gear. Most trailers have a standard winch assembly bolt pattern, so if your winch is inadequate, you can replace it easily.
Some people recommend winch size using the boat length. This is only a general guideline. Some boats by their design and construction (in addition to factors such as gasoline capacity, pounds of ice, fish, and other items) may drastically increase the overall weight of the boat. Additionally, winches are designed to pull weight, not length. To be sure you're selecting the proper winch you should find out your boat's weight and estimate its overall payload (gear, fuel, water, etc.) Always err on the side of too big.
To avoid chafe on the winch line or strap, be sure it doesn't rub against any sharp edges on the winch stand or trailer. If frayed or worn spots appear, replace the winch line immediately with a new rope, strap, or cable of the proper type, size, and strength.