This paper develops a LED fishing lamp mounting system which slides in and out a LED fishing lamp mounting rack according to fishing situation of a fishing boat. Sliding mechanism of the LED fishing lamp mounting system is realized with a rack and pinion. Components of the LED fishing lamp mounting system are modeled with finite elements. In addition, the LED fishing lamp mounting system is modeled with rigid bodies. A rigid body model of the LED fishing lamp mounting system is interfaced with finite element component models to develop a computational model of the LED fishing lamp mounting system. A simulation is performed with the developed computational model for dynamic stress analysis of the LED fishing lamp mounting system. A bouncing, rolling, and pitching motion which describe a very rough sea are used as input conditions for the simulation. Six cases are considered for the simulation based on the number of fishing lamp and the location of sliding rack.