▁ships . ▁ ▁Con cept ▁The ▁Sch illing ▁profile ▁is ▁designed ▁to ▁improve ▁the ▁effective ▁lift ▁generated ▁by ▁the ▁rud der ▁and ▁hence ▁improve ▁the ▁man eu ver ability ▁of ▁the ▁craft , ▁especially ▁at ▁slow ▁spe eds . ▁The ▁rud der ▁is ▁effective ▁in ▁both ▁forward ▁and ▁reverse . ▁It ▁has ▁been ▁claimed ▁that ▁a ▁Sch illing ▁rud der ▁" comb ines ▁the ▁highest ▁later al ▁forces ▁with ▁the ▁best ▁course ▁stability . ▁ ▁Use ▁Like ▁all ▁rud ders , ▁the ▁main ▁effect ▁of ▁a ▁Sch illing ▁rud der ▁is ▁to ▁def lect ▁the ▁flow ▁of ▁water ▁generated ▁by ▁the ▁prop eller . ▁Sch illing ▁rud ders ▁are ▁most ▁commonly ▁used ▁on ▁ships ▁that ▁are ▁difficult ▁to ▁man eu ver , ▁particularly ▁large ▁ships ▁such ▁as ▁container ▁ships ▁and ▁oil ▁tank ers , ▁slow - mov ing ▁ships ▁and ▁boats , ▁longer ▁and ▁nar ro wer ▁ships , ▁or ▁boats ▁with ▁slow - mov ing ▁prop ellers . ▁ ▁Additionally , ▁a ▁tw in - r ud der ▁configuration ▁and / or ▁a ▁bow ▁thr uster ▁can ▁significantly ▁contribute ▁to ▁the ▁man eu ver ability ▁of ▁even ▁the ▁largest ▁ships . ▁When ▁the ▁rud ders ▁are ▁at ▁angles ▁of ▁ 9 0 ▁degrees ▁or ▁more ▁to ▁the ▁direction ▁of ▁the ▁prop eller ▁generated ▁thrust , ▁they ▁can ▁direct ▁the ▁thrust ▁forward ▁and ▁provide ▁a ▁significant ▁bra king ▁effect ▁on ▁the ▁ship . ▁ ▁Sh ape ▁There ▁is ▁little ▁reliable ▁information ▁available ▁in ▁the ▁public ▁domain ▁regarding ▁the ▁exact ▁shape ▁of ▁the ▁Sch