Human errors can cause leaks, too, such as by breaking off the knotmeter impeller's thru-hull by a careless step when cleaning the bilge.
Iimpazame zomntu zingabongela ukuvuza, njenge kuqhekeka kwe-knotmeter impellens thru-hull ngenxa yenyothele elingenanka -- thale xa kucocwa umphantsi.