Which is not a primary consideration for a mariner when choosing a navigational route?

When considering navigational routes, the weight of the cargo is not typically a primary consideration for a mariner. While it can influence specific operational aspects, such as stability and fuel efficiency, the direct factors that primarily affect navigation are more centered around the safety and viability of the route itself.

Water depth is crucial for ensuring that a vessel can safely pass without running aground. Weather conditions are vital as they can significantly impact visibility, vessel handling, and overall safety. Potential hazards, such as other vessels, reefs, or obstructions, also play a central role in route planning to avoid dangerous situations. Unlike these factors, cargo weight tends to be less influential on the choice of navigational routes but more relevant in terms of vessel stability and performance during the journey.