In 1843 an observatory was built here for astronomical and meteorological observations and to provide accurate time for ships' chronometers.

[2] In 1866, when the dock was redeveloped, the observatory was relocated to Bidston Hill on the Wirral Peninsula.

[4] Initially planned eleven years earlier, the lock entrance from the Mersey was finally opened in 1949.

The entrance channel from the river and part of the dock has since been filled.

In 2007, work began on a £20 million extension of the Leeds and Liverpool Canal, providing a further 1.4 mi (2.3 km) of navigable waterway and encompassing Princes Half Tide Dock.