For leveling, which statement is true?

• A. Bubble level alone is sufficient
• B. Bubble level is a good indicator but a 4 ft carpenter level should be used for leveling
• C. Carpenter level is not used at all
• D. Bubble level provides no leveling information

Answer: (B)

A quick, point-by-point reading comes from a bubble level, but true leveling over a longer surface needs a longer tool to verify the entire span. A four-foot carpenter level is designed to read level across a longer distance, making it much easier to detect bowing, twist, or any unevenness along the length. In crane setup, you’d use the bubble level for an initial check and then confirm and finalize the reading with the longer carpenter level to ensure the base is truly level along its full length. That’s why this approach—using the bubble level as a quick indicator and bringing in a longer carpenter level for the final leveling—is the best practice.