In order for the exemption to apply, the employees must be engaged ``in transportation'' of the specified harvest workers between the points stated in the statute. Actual engagement ``in transportation'' of such workers is required. Engagement in other activities is not exempt work. Drivers, driver's helpers, and others who are engaged in the actual movement of the persons transported may qualify for the exemption. Office employees, garage mechanics, and other employees of the employer who may perform supporting activities but do not engage in the actual transportation work do not come within the exemption. There is no restriction in the statute as to the means of conveyance used; the exempt transportation may be by land, air, or water in any vehicle or conveyance appropriate for the purpose. Employees of any employer who are engaged in the specified transportation activities may qualify for exemption; it is not necessary that the transportation be performed by the farmer. (See Sec. 780.905.)