While we are not told the timing of this part of the journey, there is no indication of any significant halt in movement as there is in verse 13 below. It appears logical that they the Jaredites have come along the valley of one of the rivers, and arrived at a location where the next phase of their journey must be over water. The logical possibilities are either the Black Sea or the Mediterranean, with the Mediterranean being the ultimate body of water regardless of the location of the original embarkation. The most likely scenario would appear to have the Jaredites build barges and sail west across the Mediterranean, stopping perhaps in northern Africa, Southern Spain, or Portugal. While Allen notes this possibility, he suggests:
“If the Jaredites crossed the Mediterranean and eventually ended up in, let us say, Morocco or Poretugal, they would then be on the borders of the great Atlantic Ocean. The mountains of Spain may have been the area described as “beyond the sea [Mediterranean] in the wilderness.” At this point, this alternative lacks credibility.” (Joseph L. Allen. Exploring the Lands of the Book of Mormon. S.A. Publishers, 1989, p. 259).
Allen does not tell us why this alternative lacks credibility, other than the rather obvious fact that he doesn’t believe it. What he never does is tell us where this original journey that required barges might have occurred in the eastward journey that he favors to have the Jaredites arrive at the Pacific. Our text requires two journeys over many waters in barges, not one. The sequence in the text tells us that they follow a valley, which might be formed by a river, and then they set sail in barges, stopping on a shore where they are also ready to launch to the “great sea which divideth the land.” (Ether 2:13). It would appear that they land on a shore, and that very shore is the next departure point. Only the westward movement across the Atlantic makes sense of this description.