Question 529 Deck General

The correct answer is B) Overloading. Overloading a vessel is an example of failure to exercise due diligence, as it compromises the vessel's stability and seaworthiness. Overloading a vessel beyond its maximum capacity or load line can make it unstable and more prone to capsizing or sinking, which would be a violation of the requirement to exercise due diligence in operating the vessel safely. The other options, while potentially problematic, do not directly relate to the concept of due diligence in the same way as overloading. Sailing with less than 30% reserve fuel, sailing short of being fully loaded, or sailing short of union manning requirements may be issues, but they do not necessarily constitute a failure to exercise due diligence in the same way as overloading the vessel.