Great Loop Tool

Bridge Clearance Worksheet

The famous low-clearance conversations are really about uncertainty. This worksheet helps capture the exact measurement, the removable gear, and the verification steps before a low bridge becomes a high-stress moment.

Maintained by TheCenterOf editors. Last reviewed: 2026-06-10. This page is a planning aid, not navigation, legal, insurance, mechanical, or safety advice. Verify current charts, notices, bridge and lock information, weather, marina terms, insurance language, and local rules before acting.

Clearance estimate

Published bridge clearance (feet)

Measured boat air draft (feet)

Extra water level / tide / uncertainty (feet)

Comfort margin wanted (feet)

Measure these before believing the number

Radar arch top
Antennas up and down
Anchor light
Canvas and frame
Solar mounts
Dinghy davits if relevant
Water tank full/empty effect
Fuel load effect
Published clearance datum
Current gauge or lock/bridge notice