Liquefied natural gas vessels are one of the most sophisticated ships in the merchant navy. No other type of cargo ship has that amount of various equipment used for cargo handling operations. The paper analyses the previous operations of the loading and transportation of liquefied natural gases (LNG) by sea with an emphasis on the planning of the loading of cargo on board, the preparation of the vessel for the loading of liquefied gas and ultimately the transportation of said cargo by sea. The transport of liquefied natural gases by sea is a specific and often challenging job due to the characteristics of the cargo liquefying at -161 ° C and only at this temperature is gas transport possible. Cargo handling and maintenance is handled by deck officers who, due to the cargo characteristics themselves, often face problems with loading, transporting and maintaining cargo. The aim of this paper is to thoroughly analyse and approximate the ways of preparing a ship for the transport of liquefied natural gases, and to bring to the reader the challenges that deck officers on such ships regularly face for the purpose of quality and professional handling and transportation of natural liquefied gas by sea.