Vertical Clearance Calculator
Calculate safe passage under bridges and overhead obstacles. Account for tide heights, vessel air draft, and safety margins.
Vertical Clearance Calculator
Highest Astronomical Tide for this location
Predicted tide height when you arrive
Highest point above waterline
Additional clearance buffer
How to Use
- • Enter bridge clearance height at HAT (from charts)
- • Input the HAT value for your location
- • Enter predicted tide height at your arrival time
- • Input vessel air draft and desired safety margin
- • Calculator determines if passage is safe using HAT methodology
⚠ Safety Notice
This calculator uses HAT-based methodology for planning purposes only. Always verify with current charts, tide tables, and local authorities. Consider wave action, vessel squat, and other factors.