Abstract:
                                      In order to prevent the fishery boat workers from confusing the rules in the work of checking stabilities of domestic fishing boats and ocean going fishing boats,and reduce the risk of misuse,the paper compared and summarized the differences of practical stability criterion methods between domestic fishing boats and ocean going fishing boats,and put forward the deduction of initial stability height under longitudinal inclination.Through comparison,we found that:1)Although the mathematical models of the two stability criteria were different,the basic principles were consistent,they both put forward the requirement of weather criterion number K ≥ 1.2)The formulas to calculate the wind heeling arm were the same,but the methods of taking values of the wind pressure P and wind acting lever Z were different.3)The formulas to calculate the roll angle were different,and the meanings of initial stability height GM and ship length L were different in formula.4)No matter what kind of operation,the ocean going fishing boats had the minimum requirement for the area under the righting arm curve,while the domestic fishing boats had the minimum requirement for the area under the righting arm curve only when the operation mode was a beam trawl.In addition,in the work of checking stability,we should also pay attention to that:the weight of the objects which won't move and won't reduce weight after shipment should be included in the weight of the empty ship;the weight of the fishing nets and rigging should be calculated in the wet weight state;the enclosed structure such as the superstructure or deck room which was included in the calculation of stability should comply with the relevant requirements of the rules in the freeboard;the inlet angle of the free surface,the suspension load,the fishing gear operation,the heeling moment and the longitudinal direction should be corrected according to the actual situation.This paper also proposed some opinions on how to calculate the initial stability height under the state of longitudinal inclination.