On the 28th ONS 5 arrived at the "Star" patrol area, and was sighted at 0900 by "U-650". "U-650" held contact despite being forced to dive three times to avoid approaching aircraft at 1014, 1150 and 1518. By nightfall "U-650" had been joined by "U-375", "U-386", "U-528" and "U-537". The U-boats' contact reports alerted Commander Gretton to the presence of U-boats on the convoy's port bow, beam, and quarter and astern. "Duncan" and "Tay" made an unsuccessful depth charge attack after sighting a U-boat on the port bow at 1830.