A C.2 board before a bridge shows 3.50 m. What is the defensible pre-entry check for a boat with 3.20 m maximum air draught?
Short answer
Calculate the 0.30 m nominal difference, then verify the local reference, current level and vessel configuration
C.2 limits headroom and may carry metres. The arithmetic is 3.50 - 3.20 = 0.30 m, but that result is only nominal until the current waterway reference, level, boat configuration and uncertainty agree. Revisit Restrictions, Recommendations and Information.
Sources and scope
Reviewed by Richard Moore on . This answer is scoped to european inland waterways; local rules still apply; check the current chart, publication, local rules and official operational guidance before acting afloat.
Quick check
A C.2 board before a bridge shows 3.50 m. What is the defensible pre-entry check for a boat with 3.20 m maximum air draught?