Great Loop Flagship Guide
Great Loop Air Draft Planning Guide
Air draft planning should start with a tape measure, not a forum argument. The route gets calmer when the crew knows the actual height and the removable pieces.
Quick decision map
Measure the real boat
Measure from the waterline to the highest fixed point with typical cruising load. Repeat after major load changes or gear changes....
Separate fixed and removable height
Know what lowers quickly, what requires tools, what needs two people, and what cannot be lowered safely underway. Practice before ...
Understand published clearance
Bridge boards, charted clearances, tides, river levels, wind setup, and lock/dam conditions can disagree. Use current local inform...
Build a margin habit
A plan that depends on inches is not a comfortable plan. Margin protects against measurement error, water-level changes, wake, and...
Measure the real boat
Measure from the waterline to the highest fixed point with typical cruising load. Repeat after major load changes or gear changes. Listing numbers are only a starting point.
Separate fixed and removable height
Know what lowers quickly, what requires tools, what needs two people, and what cannot be lowered safely underway. Practice before the bridge day.
Understand published clearance
Bridge boards, charted clearances, tides, river levels, wind setup, and lock/dam conditions can disagree. Use current local information.
Build a margin habit
A plan that depends on inches is not a comfortable plan. Margin protects against measurement error, water-level changes, wake, and human nerves.
Useful next step
Turn this page into a boat-specific note. Write down the current assumption, the proof you have, and the next verification step. The best Great Loop planning habit is making vague confidence visible before it becomes expensive.
Related tools: Great Loop Tools, Fuel Range Calculator, Trip Pace Planner.
Air draft needs a written playbook
Air draft planning is less stressful when the crew has already written the playbook. The boat should have a normal height, a reduced height, and a minimum height, with exact notes on what must be lowered or removed to reach each number.
The number should be measured in cruising trim and updated when gear changes. Antennas, radar, anchor lights, canvas, solar panels, davits, and dinghy gear can all change the answer.
Planning checks
- Measure from the waterline with typical fuel, water, dinghy, and cruising gear aboard.
- Practice the removal or lowering sequence at the dock before a bridge day.
- Check water levels and bridge boards against your written number, not memory.
- Keep tools and storage plans ready for anything removed before a low bridge.
Publication notes
Written and maintained by TheCenterOf editors. Last reviewed: 2026-07-06. This page is planning guidance for boating and Great Loop readers. It is not a substitute for current charts, notices, marina confirmation, weather forecasts, official rules, professional advice, or onboard judgment.
Corrections, broken links, and first-hand route updates are welcome through the contact and corrections page.
Official sources to verify
Use this page as a planning framework, then verify current details before making route, safety, insurance, customs, or departure decisions.