Via https://www.facebook.com/photo.php?fbid=10153510983496667&set=o.51847398...

The Hayle Harbour Trust is investigating whether it might be possible to restore a causeway across from the Spit to Lelant Quay. The first image shows the approximate original route from the late 1700s in yellow and a shorter route in green. Would anyone object to this? The Harbour Master has given preliminary support since Lelant Water is not considered a navigable waterway. It would not affect the ability of vessels to pass up there at high tide and would permit foot traffic for quite a large percentage of the day. It would make a nice connection/short cut on the Coastal Footpath.

And here's a map of the footpaths across Lelant Water in 1828, just after the Causeway was opened (1825).