Below bridges (BB)

This term can be Found in instructions from port and charterers’ agents to the ship to ensure that the ship is kept at the appropriate draft in order to ensure that it will have sufficient clearance above its highest point to pass safely below bridges (or overhead obstructions such as power cables) across a canal, channel or river in the approaches to a berth or port. To ensure the ship’s clearance below bridges would be the shipowner’s obligation.