In nautical parlance this is called "Bringing up.” In shoal-water the depth is found by the hand lead-line and small hand-lead.
Ngentetho eqhelekileyo yasenqanaweni le nto ibizwa ngokuba `Khulisa'.Kwisidibi samanzi ubunzulu bufumaneke ngomgca wesikhokelo sesandla kwakunye nesikhokelo sesandla esincinane.