"Amphitrite" cleared Bridgeport, Connecticut, on 2 February 1917 for repairs and alterations at the New York Navy Yard, arriving the following day, 2 February. On 17 February, the ship departed the yard and stood down river to the Narrows, near Rosebank, Staten Island, NY, for work on the submarine net in company with three tugs, "Hudson", "W. J. Conway", and "Lizzie D.", and Navy lighters , "Transport", and the tug "S. W. Holbrook". Later, in company with "M. M. Millard", "George T. Kirkham", and "John Nichols", she continued her work laying the net off Rosebank.