What effect does added buoyancy have on ascent rate?

When considering the impact of added buoyancy on ascent rate, it is important to understand how buoyancy affects a diver's vertical movement in the water. Buoyancy refers to the ability of an object to float or rise in a fluid, and when a diver adds buoyancy—such as through the use of a buoyancy control device (BCD) or by adding air to a suit—it becomes easier for them to ascend. This increase in buoyancy can lead to a higher ascent rate because the added buoyancy reduces the diver's weight relative to the surrounding water, allowing them to rise more quickly.

However, this increase in ascent rate can complicate safety stops. Safety stops are critical for divers to allow excess nitrogen absorbed during the dive to be released from the body and to minimize the risk of decompression sickness. With an increased ascent rate due to added buoyancy, a diver may ascend too quickly to effectively perform these safety stops. As a result, managing a controlled ascent becomes more challenging, necessitating greater attention to buoyancy control to ensure proper ascent speed and the completion of safety stops.

Thus, the correct answer reflects that added buoyancy increases the ascent rate, making safety stops more difficult to manage properly.