When diving at an altitude above 1000 feet, what special consideration must be taken?

At higher altitudes, the atmospheric pressure is lower, which affects the body's absorption of nitrogen during a dive. Adjusting the dive computer for altitude is essential because standard dive tables and computers are calibrated for sea level conditions. Failing to adjust the dive computer can lead to incorrect readings regarding no-decompression limits and surface intervals, increasing the risk of decompression sickness. This adjustment ensures that the diver can accurately track their dive profile and remain within safe limits while also accounting for less ambient pressure in the environment.

While other options may seem relevant, they do not directly address the critical need for accurate dive planning and safety measures specific to altitude diving.