A Type B-100 vessel must have which of the following features to qualify for a freeboard reduction?

To qualify for a freeboard reduction on a Type B-100 vessel, it is essential that the vessel be equipped with steel hatch covers that are weather-tight. Weather-tight hatches play a crucial role in enhancing the vessel's ability to withstand sea conditions, reducing the risk of water ingress. This structural integrity and watertightness allow the vessel to maintain a lower freeboard, as it indicates a higher level of safety and seaworthiness under specific operating conditions.

The other options may not directly address the criteria for reducing freeboard according to the regulations governing vessel stability and safety. While an open deck with no access could pose safety risks, it does not inherently contribute to the structural safety required for freeboard reduction. Similarly, having no crew access aboard or a minimum length specification may relate to operational or safety standards, but these factors alone do not satisfy the technical requirements for freeboard adjustments. The emphasis on weather-tight features underscores the need for robust design to ensure vessel stability and safety when operating in various marine environments.