According to Warren and Palmer, it is unlikely that the first set of Jaredite barges was completely enclosed, because enclosure posed added construction challenges. Thus, we can assume that the first set of barges was a rehearsal for the construction of the second set. The first set of barges probably had a rudder. When the second set was built, totally enclosed, they asked not only "whither shall we steer? (Ether 2:19) but exclaimed "in them we cannot breathe!" (Ether 2:19) and "behold, O Lord, in them there is no light!" (Ether 2:19). [Bruce W. Warren and David A. Palmer, The Jaredite Saga, ch. 5, unpublished]
In Them is No Light in Them We Cannot Breathe
Paul Hedengren notes that the Jaredites constructed two sets of barges. After leaving the valley of Nimrod, the Jaredites traveled in the wilderness for a while, built barges, crossed "many waters" (Ether 2:6) and then traveled in the wilderness to "that great sea which divideth the lands" (Ether 2:13) before finally being directed to build barges again. Of the second set of barges we read, "And the Lord said: Go to work and build, after the manner of barges which ye have hitherto built" (Ether 2:16).
There are some indications, however, that the design of the second set of barges was not exactly like the first. The phrasing "after the manner" permits possible accommodations for a much longer and more arduous ocean voyage.
For the first set of barges, apparently the deck only needed to keep rain and occasional boarding waves from flowing down into the vessel. As a consequence, this lighter deck contained sufficient openings to provide adequate ventilation and needed light below.
For the Jaredite ocean voyage, however, the waves were so high that "they were many times buried in the depths of the sea, because of the mountain waves which broke upon them" (Ether 6:6) To do this, the force exerted on the deck would have been much greater than was normally exerted on the hull. Thus the deck must have been very strong. To achieve this strength, traditional openings for ventilation and light were apparently not possible.
Thus the reader should notice that only with the second construction of barges are concerns about the absence of light and ventilation expressed. As the brother of Jared says, "Oh Lord, in them there is no light . . . And also we shall perish, for in them we cannot breathe" (Ether 2:19). [Paul Hedengren, The Land of Lehi: Further Evidence for the Book of Mormon, pp. 77-78]