Demand for improvement in shipbuilding is increasing and due to this many manufacturing industries are developed rapidly and come up with very advanced designs and development in this field. Specifically, there is a good scope for improvements in the structure of the Class 6 catamaran hull spine beam. Usually, the multihull catamaran operates beyond its design specifications and due to unforeseen winds, waves, and deteriorating weather, the hull spine beam faces more impacts what leads to failure and weakening after decades of sustained operation. The analysis results obtained in this paper show great improvement in the design of the catamaran hull spine beam, which would give an idea of overall improvement in catamaran design and its performance. The design methods for developing catamaran and bulkheads are considered in the study. The whole analysis is performed on ANSYS software by following step by step simulation procedure using the FEM methodology. At first, simulation of simple the 3D model without considering bulkheads is done and results are observed. In the next steps, bulkheads are added to the spine beam at equal distance in a sequence of 1,3,5,7, and 9 along the beam. The obtained results confirm that adding more and more bulkheads makes the structure bulky, but adding it up to a certain level helps reduce maximum Von-Mises stress by 75.9% and total deformation of the spine beam by 70.9%, which makes the structure more rigid and essentially improves the strength of the catamaran hull spine beam.