 In late medieval times, salmon weirs hindered free passage on the river, but the Wye Navigation Act in 1662 enabled the river's potential to be developed.By 1727 shallow draught boats could get upstream beyond Hereford, and a significant shipbuilding industry developed at Monmouth, Llandogo, Brockweir and Chepstow.However, by 1835 it was stated that the Wye ""can scarcely be considered a commercial highway"" above Monmouth, and by the 1880s Brockweir bridge was the effective upper limit of navigation.