Passage: The British ships approached the German ships head on, which permitted them to use only their forward guns; Bismarck and Prinz Eugen could fire full broadsides. Several minutes after opening fire, Holland ordered a 20° turn to port, which would allow his ships to engage with their rear gun turrets. Both German ships concentrated their fire on Hood. About a minute after opening fire, Prinz Eugen scored a hit with a high-explosive 20.3 cm (8.0 in) shell; the explosion detonated unrotated projectile ammunition and started a large fire, which was quickly extinguished. After firing three four-gun salvoes, Schneider had found the range to Hood; he immediately ordered rapid-fire salvoes from Bismarck's eight 38 cm guns. He also ordered the ship's 15 cm secondary guns to engage Prince of Wales. Holland then ordered a second 20° turn to port, to bring his ships on a parallel course with Bismarck and Prinz Eugen. Lütjens ordered Prinz Eugen to shift fire and target Prince of Wales, to keep both of his opponents under fire. Within a few minutes, Prinz Eugen scored a pair of hits on the battleship that started a small fire.Lütjens then ordered Prinz Eugen to drop behind Bismarck, so she could continue to monitor the location of Norfolk and Suffolk, which were still 10 to 12 nmi (19 to 22 km; 12 to 14 mi) to the east. At 06:00, Hood was completing the second turn to port when Bismarck's fifth salvo hit. Two of the shells landed short, striking the water close to the ship, but at least one of the 38 cm armour-piercing shells struck Hood and penetrated her thin deck armour. The shell reached Hood's rear ammunition magazine and detonated 112 t (110 long tons) of cordite propellant. The massive explosion broke the back of the ship between the main mast and the rear funnel; the forward section continued to move forward briefly before the in-rushing water caused the bow to rise into the air at a steep angle. The stern also rose as water rushed into the ripped-open compartments. Schneider exclaimed "He is sinking!" over the...

Question: What did Holland want to engage with by ordering a 20 degree turn to port,
rear gun turrets