By February, 1917, this auxiliary topsail schooner was ready for sea as a disguised man-of-war, with a couple of 12-pounders cleverly concealed on her deck. She had changed her name from _First Prize_ to _Prize_, alias Q 21, and in command of her went Lieutenant W. E. Sanders, R.N.R., whom we saw behaving with distinction when serving in the Q-sailing-ship _Helgoland_. No better man could have been found than this plucky New Zealander, and he had already shown that he had a genius for this extra special type of Q-ship work. _Prize_ had been sent to work in the western waters, and on April 26, 1917, she left Milford Haven for a cruise off the west coast of Ireland, this being the month when, of all months in the war, German submarines were the most successful. At 8.35 on the evening of April 30, _Prize_ was in Lat. 49.44 N., Long. 11.42 W. It was fine, clear, spring-like weather, with a light N.N.E. wind, calm sea, and good visibility. _Prize_ was under all sail, steering on a north-west course, and making about 2 knots. Two miles away on her port beam, and steering a parallel course, was sighted a big submarine. This was U 93, a most modern craft, commanded by one of Germany’s ablest submarine officers, Lieut.-Commander Freiherr von Spiegel. She was a powerful vessel, who had relieved U 43 on this station, and was over 200 feet long, armed with two 10·5-centimetre guns, 500 rounds of ammunition, and 18 torpedoes, her complement consisting of 37 officers and men. This latest submarine was on her maiden trip in the Atlantic, having left Emden on Friday, April 13. For those who are superstitious the day and the date will be interesting. She had had a most successful cruise, having sunk eleven merchantmen, and was now on her way back to Germany. Von Spiegel was anxious to be back home as soon as possible, for, be it said, he was certainly a sportsman, and he happened to have a couple of horses running in the Berlin races in the second week of May.