Compensating tanks are fitted so that the weight of the submarine can be adjusted during a patrol to allow for the change of density of sea water, the compression of the hull when dived, and for the consumption of stores, provisions and fuel .
Amatanki athuthuzelayo afakiwe ukwenzela ukuba ubunzima benkwili bubenokulungelelaniseka ngexesha lokupatrola ukwenzela ukuba kubekho uguquko kubunzima bamanzi, kunxinzeleleko lwamanzi xa ithe yantywila, kunye nokufunxa kwezitora, izibonelelo kunye nesibasi.