Attribute: Vertical clearance

Acronym: VERCLR

Code: 181

Attribute type: F


The vertical clearance measured from the plane towards the object overhead.

ENC Condition:

# Must be encoded for BRIDGE objects over navigable water that are non-opening.
# Must be encoded for CBLOHD objects over navigable water if attribute VERCSA is not known.
# Must be encoded for CONVYR objects over navigable water.
# Must be encoded for PIPOHD objects over navigable water.


INT 1: ID 25-28;

M-4: 380; 380.1; 382; 383;

Minimum Value: 0


Unit: defined in the HUNI subfield of the DSPM record or in the HUNITS attribute of the M_UNIT meta object class, e.g. metre (m)

Resolution: 0.1 m or 0.1 ft




7.6 for a vertical clearance of 7.6 metres.


In the case of cables carrying high voltages an additional clearance of from 2 to 5 metres may be needed to avoid an electrical discharge. When known, the authorized safe clearance (known in the UK as the Safe Overhead Clearance) which is the physical clearance minus a safety margin shall be stated. (IHO Chart Specifications, M-4).

See also 'vertical clearance safe'.