In the current scenario of the world economy, it is essential to increase the integration between the different players in the companies supply chain, reducing operational costs, and improving efficiency. Ship routing is a substantial part of this integration regarding global maritime commerce, being the object of study by many authors. In this work, we present different methodologies to solve variants of the Maritime Inventory Routing Problem. This problem involves a large number of variables and is a computationally complex problem to solve. Our primary motivation is to solve a ship routing real case of a large company in the Oil and Gas sector, achieving high-quality solutions in plausible processing times and improving companies current results. All developed methodologies are based on a metaheuristic combination with a linear mathematical model. One of the main differences between the methodologies lies in the mathematical model to solve the inventory problem, where we tested discrete-time and continuous-time approaches. Other differences concern the number of evaluated products (single or multi-product) and the metaheuristic used (local search heuristics with a Simulated Annealing probability factor or Hybrid Variable Neighborhood Search). For the methodology using the discretetime model, the results are satisfactory, with low and punctual inventory violations in an acceptable computational time. For the methodology using the continuous-time model, the results are better once, in reduced computational time, inventory violations remain low or non-existent, depending on the scenario evaluated and the metaheuristic used. The results obtained in this work are remarkable and allow its practical application for real cases.