Fixed Jacks. The Lift: Fixed tongue jacks such as the Fulton 2,500-pound heavy-duty drop-leg, bolt-on model ($139.99; trailerandtruck parts.com) offer greater load capacities than swing jacks to ...

Most ­boat-trailer jacks are operated manually. The boater cranks the handle to move the jack up and down and raise or lower the boat. Other jacks are available today that work ­using an electric ...