(1) The fast moving currents formed by narrow channels and obstructions in the water. (2) The increase in revolutions when the propeller is lifted, or partially lifted, out of the water by the pitching motion of the vessel.
(1) Imisinga ehamba ngokukhawuleza eyenziwa yimijelo enciphileyo kunye nezithintelo emanzini. (2) Kukwanda kokujikeleza kweqhubi xa siphakanyiselwe, okanye siphakanyiselwe kancinci, ngaphandle emanzini kukuhamba kwenqanawa.