▁a ▁w reck ▁site , ▁several ▁things ▁must ▁be ▁done ▁to ▁make ▁it ▁safe ▁for ▁the ▁marine ▁environment ▁and ▁divers . ▁To ▁protect ▁the ▁environment , ▁the ▁ship ▁is ▁p urg ed ▁of ▁all ▁o ils , ▁hyd ra ul ic ▁flu ids , ▁and ▁dangerous ▁chemical s ▁such ▁as ▁PC B s . ▁Much ▁of ▁the ▁super structure ▁may ▁be ▁removed ▁to ▁prevent ▁the ▁ha z ard ▁of ▁it ▁eventually ▁c aving ▁in ▁from ▁cor ros ion . ▁Similarly , ▁the ▁interior ▁of ▁the ▁ship ▁is ▁g utt ed ▁of ▁components ▁that ▁cor ro de ▁quickly , ▁and ▁would ▁be ▁dangerous ▁to ▁divers ▁if ▁they ▁came ▁loose . ▁The ▁ship ▁is ▁thoroughly ▁clean ed , ▁often ▁with ▁the ▁help ▁of ▁volunte ers ▁interested ▁in ▁div ing . ▁A ▁significant ▁part ▁of ▁the ▁cost ▁of ▁prepar ing ▁and ▁s inking ▁the ▁ship ▁may ▁be ▁recovered ▁from ▁scra pping ▁the ▁contents ▁of ▁the ▁ship , ▁including ▁valuable ▁materials ▁such ▁as ▁co pper ▁w iring . ▁The ▁h ulk ' s ▁suit ability ▁as ▁a ▁div ing ▁site ▁may ▁be ▁en hanced ▁by ▁cutting ▁open ings ▁in ▁its ▁h ull ▁and ▁interior ▁bulk head s , ▁and ▁removing ▁doors ▁and ▁h atch ▁covers ▁to ▁allow ▁divers ▁access ▁at ▁reduced ▁risk . ▁ ▁S inking ▁ ▁The ▁prepar ation ▁phase ▁usually ▁removes ▁a ▁significant ▁amount ▁of ▁weight , ▁so ▁the ▁ship ▁flo ats ▁higher ▁in ▁the ▁water ▁than ▁normal . ▁This ▁may ▁make ▁it ▁necessary ▁to ▁stabil ise ▁the ▁vessel ▁by ▁filling ▁some ▁compart ments ▁with