Which statement about altitude and RGBM usage is true?

Which statement about altitude and RGBM usage is true?

• A. The tables are valid only at sea level
• B. They cannot be used above 1000 m
• C. They can be used at elevations up to 3048 m
• D. Elevation has no impact on table use

Answer: (C)

Altitude changes surface pressure, which in turn affects nitrogen loading and the decompression calculations used by RGBM. The RGBM tables account for that pressure variation and are designed to be applicable up to about 3048 meters (roughly 10,000 feet). Beyond that height, the standard tables aren’t reliable and you’d use altitude-adjusted resources or a dive computer set for altitude. So, using RGBM tables up to 3048 meters is the true approach. The idea that they’re valid only at sea level, unusable above 1000 meters, or unaffected by elevation isn’t accurate.

Altitude changes surface pressure, which in turn affects nitrogen loading and the decompression calculations used by RGBM. The RGBM tables account for that pressure variation and are designed to be applicable up to about 3048 meters (roughly 10,000 feet). Beyond that height, the standard tables aren’t reliable and you’d use altitude-adjusted resources or a dive computer set for altitude. So, using RGBM tables up to 3048 meters is the true approach. The idea that they’re valid only at sea level, unusable above 1000 meters, or unaffected by elevation isn’t accurate.