That would depend on the journey. One extreme is a ship going from Egypt to Egypt, with nearly 100% of the desired journey being the canal. Another possibilit

That would depend on the journey. One extreme is a ship going from Egypt to Egypt, with nearly 100% of the desired journey being the canal. Another possibility is Perth to Miami. That one can easily go either way around Antarctica, and if the ship is small enough it can go eastbound through the Panama Canal. A less extreme example would be Singapore to Boston.