Alma 22:32

And now it was only the distance of a day and a half’s journey for a Nephite, on the line Bountiful, and the land Desolation, from the East to the West sea; and thus the land of Nephi, and the land of Zarahemla, was nearly surrounded by water; there being a small neck of land between the land northward, and the land southward.

It was only a day and a half’s journey for a Nephite on the line between Bountiful and the land Desolation from the east to the west sea. The land of Nephi and the land of Zarahemla were almost surrounded by water. There was a small neck of land between the land to the north and the land to the south.

The distance from the eastern sea to the western sea along the border between Bountiful and Desolation was only a day and a half’s journey for a Nephite. This meant the land of Nephi and the land of Zarahemla were nearly surrounded by water, with just a small strip of land connecting the northern and southern lands.