Land means location in this context. Filling in seabed (which are literally termed "water parcels" as a term of art) to make dry land is technically improving it. The straightforward policy recommendation is therefore to exempt reclaimed land from taxation (perfectly in line with a policy of not taxing improvements) for e.g. the first 50 or so years (well past the investment horizon) and begin taxing it as conventional land thereafter -- this comports with George's philosophy for how to handle edge cases like e.g. landscaping that start off as improvements but over a long enough time horizon eventually become regarded as part of the permanent landscape.

Alternatively, reclaimed land is usually a state initiated enterprise in most cases. In those situations, the land can simply be leased out by the state. This is literally what NYC did with Battery Park city!

https://blog.landeconomics.org/p/georgism-through-land-leasi...