What should be done if a diver cannot clear to 50' in the chamber during a Sur 'D' dive?

When a diver cannot clear to 50 feet in the chamber during a Sur 'D' dive, compressing the diver to the highest depth achievable is the appropriate action. This is crucial because it allows for the gradual equalization of pressure within the diver's body, which can help prevent barotrauma or other pressure-related injuries. The process of compressing the diver creates a safer environment where the pressure is managed better, and it provides an opportunity to reassess the diver’s ability to equalize or possibly continue the dive.

This approach prioritizes the diver's safety above immediate ascent or other actions, recognizing that rapid or uncontrolled ascents can lead to serious complications such as decompression sickness. Taking the preventive measure of higher compression ensures that the diver's physiological needs are met before making a decision on surface recovery or other interventions.