Estimation and Comparison of Accuracy in Various Data Resolutions on Optimal Ship Routing Across the North Pacific Ocean

Abstract

The amount of maritime cargo has been increasing for several decades. However, most seafarers have been shifting from lifetime employment to temporary employment. This may result in the ships lacking the adept techniques of seafarers, which significantly increases the reliance and importance of operational support systems. There are many studies on optimal ship routing, but its accuracy has not been discussed sufficiently. Especially, the grid point value on the weather database is the most important factor to discuss regarding its accuracy. In the field of meteorology, these databases have been improved to include global data in recent decades. In this study, the simulation results are compared to know the influence to the accuracy if the spatial and time resolutions vary in each condition. Optimal ship routing is computed using the isochrone method, which is one of the major methods of route analysis. Numerical simulations are conducted for a container ship between Tokyo and Los Angeles, with the weather databases of National Centers for Environmental Prediction (NCEP) and National Oceanic and Atmospheric Administration (NOAA). It is known that there are no significant differences between each resolution setting. However, the optimal voyage routes are different if the ship avoids high waves or strong winds in any direction. The accuracy is more influenced by the maneuverability in rough seas than the spatial and time resolutions of the weather databases. Accordingly, optimal ship routing must consider the actual maneuvering and speed loss theories, besides the development of a meteorological database.