Why is a decomp chart important for divers?

A decompression chart is crucial for divers because it outlines safe ascent profiles that help prevent decompression illness (DCI). When divers ascend from depths, the reduction in pressure allows dissolved gases, primarily nitrogen, to come out of solution and form bubbles. If the ascent is too rapid, these bubbles can expand and cause DCI, which may result in severe health issues. The decompression chart provides specific depth and time guidelines showing how long a diver should spend at various depths during ascent, often incorporating stop points to allow the body to safely off-gas excess nitrogen.

While the other options have their merits, they do not directly highlight the primary role of a decompression chart in ensuring diver safety related to gas absorption and elimination during ascent. The focus on preventive measures against DCI through proper ascent profiles clearly identifies the significance of the decomp chart in dive safety protocols.