The effect of the new weapon was demonstrated on 10 March 1944 when Mk XVIIIs from No. 248 Squadron RAF (escorted by four Mk VIs) engaged a German convoy of one U-boat and four destroyers, protected by 10 Junkers Ju 88. Three of the Ju 88s were shot down. Pilot Tony Phillips destroyed one Ju 88 with four shells, one of which tore an engine off the Ju 88. The U-boat was damaged. On 25 March,  was sunk by Molins-equipped Mosquitos. On 10 June,  was abandoned in the face of intense air attack from No. 248 Squadron, and was later sunk by a Consolidated B-24 Liberator of No. 206 Squadron. On 5 April 1945 Mosquitos with Molins attacked five German surface ships in the Kattegat and again demonstrated their value by setting them all on fire and sinking them. A German Sperrbrecher ("minefield breaker") was lost with all hands, with some 200 bodies being recovered by Sweden vessels. Some 900 German soldiers died in total. On 9 April, German U-boats ,  and  were spotted in formation heading for Norway. All were sunk with rockets.  and  followed on 19 April and 2 May 1945, also sunk by rockets.
Question: What was abandoned in the face of intense air attack?
Answer: U-boat