Heeling is unsafe for ship, its machineries and people on board. It is known the main reasons of vessel’s heeling such strong winds, hard and speedy turns, uneven cargo loading. The most dangerous for vessel should be the shift of cargo at sea due to faults during port cargo loading. During cargo operations, the vessel’s heel may change and ought to be under control. Some offshore vessels, pipe-lay, crane, heavy lift, container or ro-ro vessels ought to have the anti-heeling systems to prevent too high heels during port or offshore operations. They are needful for the vessel and cargo safety. It was presented chosen examples of such systems showing the solutions, elements of anti-heeling (A-H) systems, method of vessel’s heel visualization, ways of utilization etc. The proper utilization of A-H systems is the base of correct, save time and safe operations to minimize the risk of vessel’s tilting or capsizing. It was mentioned some problems during operation and some malfunctions of A-H systems creating the risk of vessel’s accidents. Some examples of famous and serious vessel’s accidents were shown. It was discussed what may be done for improving these systems during the cargo operation especially in open sea particularly necessary for offshore vessels.