The time required for the journey is one reason Joseph Allen argues for a Pacific crossing:
The Book of Ether reports that the Jaredites took 344 days, almost one year, to travel from the point of departure to the Promised Land. If the Jaredites left from the Atlantic side, near Morocco, they would have traveled in circles for 8 or 9 months. Thor Heyerdahl made the trip on a raft from Morocco to the Caribbean in two months. The scripture says, “… the wind did never cease to blow towards the promised land… ” (Ether 6:8). We would not expect the Jaredites to travel in circles. The distance from the Pacific by China to the Gulf of Tehuantepec in Mesoamerica is more than twice the Atlantic’s crossing distance, thus placing us closer to the required time for the Jaredites to travel from the Old to the New World.
Certainly when stated in that way, 344 days seems excessive for an Atlantic crossing, though Allen’s suggestion that the Pacific crossing was twice as long produces only four months’ travel as opposed to Heyerdahl’s two; 120 days is obviously more than 60, but it still falls significantly short of 344. Allen misses two important points. First, the Jaredites simply could not have carried enough food and fresh water for themselves and their livestock. A journey of nearly a year required landing to reprovision. Since their last “temporary” stop lasted four years, we cannot assume that stops to replenish supplies would have been short. Regardless of route, the necessary stop(s) would have lengthened the journey’s total time.
Second, Allen omitted from his quotation of Ether 6:8 an important phrase: “The wind did never cease to blow towards the promised land while they were upon the waters.” Allen is assuming a continuous journey with no stopping; but the italicized statement implies that there were times when they were not upon the waters. I hypothesize that they did, indeed, stop to reprovision, although the record does not say so nor, naturally, supply any clues about where they stopped nor how long. There are not many places to stop and reprovision once leaving the western coast of Africa. Perhaps their first landfall was the islands around Cuba where they stayed for a time. (See commentary accompanying Ether 2:14 for my reasons for preferring an Atlantic crossing.)