If a dive is cold or strenuous, what adjustment should be made to the dive tables to enhance safety?

When a dive is characterized as cold or strenuous, it places additional physiological stress on the diver's body. This can impact how the body absorbs and eliminates inert gases, particularly nitrogen. In cold water, blood circulation may be reduced to extremities, potentially affecting decompression and gas exchange rates. Similarly, strenuous activity increases the diver's metabolic rate, which typically results in higher nitrogen uptake due to increased breathing rates and heart rates.

By reducing the no-decompression limits, divers account for these compounding factors, thus enhancing their safety. This adjustment recognizes that any additional stress—like cold temperatures or physically demanding conditions—can increase the risk of decompression sickness. Therefore, modifying the no-decompression limits ensures that divers stay within safer parameters, minimizing the risk of nitrogen buildup in the body.

The other choices do not appropriately address the heightened risks associated with cold and strenuous dives. Increasing bottom time or adding a deeper safety stop may inadvertently lead to increased nitrogen absorption, while shallowing the dive tables without considering the conditions could lead to unsafe practices in decompression planning.