A joint excursion by the two squadrons was arranged, Rear Admiral Strauss commanding the whole, flying his flag on board _San Francisco_ again. The squadrons joined off the middle Orkneys the morning of 7 September, and began the minelaying a few miles to the northward, starting from a buoy placed by H.M.S. _Laburnum_ and removed by her after we had passed. As we were directly in the submarines’ thoroughfare, special patrols were provided, surface and air, in Fair Island Channel and also well to the southward of us. The American squadron planted six upper level lines, the British squadron planted one similar line, after the completion of which it separated to the southward, returning to its base at Grangemouth, Firth of Forth. On the way, one of them had a collision in the fog with a destroyer of its escort, which later sank in consequence. Our squadron turned north at the end of our minefield, ran taut wire to Buoy No. 5, thence paralleled the minefield at five miles distance for observation of defective mine explosions, steering west to the Orkneys and returning to the base on the reverse of the outbound courses. Fog came on soon after mining was finished, continuing intermittently until we made port. For this reason, _San Francisco_ did not cut her taut wire at Buoy 5 but kept it running until the squadron slowed to take in paravanes, near Cromarty—122 miles of wire run out, without a break. The succeeding excursion was similar, with Rear Admiral L. Clinton-Baker, R.N., in H.M.S. _Princess Margaret_, in command of the whole force, Rear Admiral Strauss again on board _San Francisco_. On the way out, it was not permitted to pass between the Orkneys and the western end of the minefield planted just previously, but instead, the squadrons were routed NW’ly, through Stronsay and Westray Firths, in the Orkneys, thence E’ly through Fair Island Channel, and down to within five miles north of the other minefield.