Brant A. Gardner discusses the imagery in Mormon 5:17-18; argues that the terms used are not from the plate text but examples of translators' anachronisms to convey the meaning on the plates.
Brant A. Gardner, Second Witness: Analytical and Contextual Commentary on the Book of Mormon, 6 vols. (Salt Lake City: Greg Kofford Books, 2007), 6:91-92
Translation: Some of Joseph’s cultural assumptions appear in the translation of Mormon’s lament. Certainly Mormon’s elegiac intention came through, but the specific language reflects either Joseph’s modern context or his familiarity with biblical language. None of the images in this last sentence were part of Mesoamerican culture. For example, “chaff” is the protective, light husk around each grain of wheat. During threshing and winnowing, this chaff is borne away by even a light breeze and is an image of impermanence in the Bible. Mesoamerica, however, did not have wheat; and neither corn nor beans, its two staple crops, have coverings comparable to chaff.
The image of a “vessel tossed about upon the waves, without sail or anchor, or without anything wherewith to steer” denotes powerlessness. Although it is a ready image in the Old World, Mesoamerican sea-going vessels were large, man-powered canoes. Sails are not known for this place and period. Similarly, the reference to steering implies the loss of the rudder, another device known in the Old World, but not in Mesoamerica. The Mesoamerican paddlers steered their canoes.