What condition increases the tabulated freeboard for wooden hatches?

The increase in tabulated freeboard for wooden hatches is specifically applicable to Type B vessels that use certain types of hatches. Type B vessels are defined under stability regulations to have specific constructions and standards that impact how freeboard is calculated.

When wooden hatches are used on these vessels, they may require adjustments to the freeboard due to their properties, such as weight and buoyancy characteristics, as well as how they contribute to the overall stability of the vessel. The standards for adjusting freeboard take into account the design and function of the hatches, along with the specific compliance measures associated with Type B vessels.

This approach ensures that the safety and seaworthiness of the vessel are maintained, considering the potential for water ingress through the hatches. Such regulations provide guidelines that help structural engineers and ship operators to make informed decisions about hatch materials and designs, ultimately enhancing the vessel's capacity for safe operation in various maritime conditions.