For deciding on an appropriate manual winch, we should consider the object that we need to pull. Take the weight of the object and divide it by two. For example, if a boat trailer needs to be pulled and it weighs 2,900 lbs., divide it by two, so we get 1,450 lbs. Therefore, a manual winch rated at 1,500 pounds would work for this job. If the object has to be supported on an incline, the weight should be divided by a factor of 1.5.