What is yacht air draft?
Air draft is the vertical distance from the waterline to the vessel's highest relevant fixed point. Depending on the yacht, that may include a mast, radar array, antenna, hardtop, tower, or other structure.
For waterfront-property access, air draft determines whether the yacht can pass beneath bridges and other overhead structures along the required marine route.
One bridge can control the entire route
Marine access is constrained by the most restrictive applicable structure along the route. A property may otherwise have deep water, a suitable dock, and direct canal access, but one fixed bridge with inadequate usable clearance can prevent access for a taller yacht.
That is why bridge clearance should be evaluated as part of the entire property-to-open-water route rather than as an isolated neighborhood characteristic.
Clearance interpretation
Why the numbers require context
Water level
Higher water can reduce the usable vertical space beneath a fixed bridge, while lower water may increase it.
Tide
In tidal waterways, available bridge clearance can vary with tide, so a published figure should not automatically be treated as a permanent real-time measurement.
Vertical datum
Bridge and vessel measurements need compatible references before a numeric clearance margin can be interpreted confidently.
Highest vessel point
Radar, antennas, masts, towers, and other equipment can determine the vessel's actual air-draft requirement.
Bridge geometry
Usable clearance can vary across a span, and the relevant navigation opening may not be represented by one simple universal number.
Operating condition
Movable bridges introduce schedules, openings, restrictions, notice requirements, and other operational considerations beyond static clearance.
Fixed bridges vs movable bridges
A fixed bridge creates a permanent overhead opening that the vessel must fit beneath under the applicable conditions.
A movable bridge may open to provide additional vertical clearance, but passage can depend on operating schedules, restrictions, advance notice, traffic, or local procedures.
Learn what “no fixed bridges” means →Air draft is vessel-specific
The same waterfront property can be accessible to one yacht and inaccessible to another. A low-profile motor yacht may pass beneath a bridge that prevents access for a taller vessel with a flybridge, tower, mast, or extensive electronics.
That makes air draft a fundamental input to yacht-oriented property search rather than a secondary detail discovered after a home has already been selected.
Avoid false precision
A calculated clearance margin is only meaningful when the vessel dimension and structure measurement are genuinely comparable. Data age, datum, tide, operating condition, and measurement uncertainty all matter.
Where those inputs are incomplete, the appropriate result may be conditional access or insufficient information rather than a confident yes-or-no determination.
Related Marine Access Guides
Evaluate the rest of the route
Bridge operations, water levels, marine conditions, and available data can change. Yacht.house marine-access information supports property discovery and due diligence and should not replace current charts, notices, local knowledge, professional navigation judgment, or on-site verification where appropriate.