StacksVerified U.S. regulatory reference

33 CFR §117.21

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
When a vessel approaches a drawbridge with the draw in the open position, the vessel shall give the opening signal. If no acknowledgment is received within 30 seconds, the vessel may proceed, with caution, through the open draw.