Under Keel Clearance Survey
What is Under Keel Clearance?
Under keel clearance refers to the minimum clearance available between the deepest point on a vessel and the seabed.
Why Conduct Under Keel Clearance Surveys?
In commercial shipping and recreational boating, under keel clearance is critical for the safety of vessel movements and navigation. The consequences of a vessel running aground have the potential to be catastrophic; therefore, maintaining a safe under keel clearance is crucial.
To maintain a safe under keel clearance you need an accurate model of the bottom of the water body. This can be achieved using a Multibeam Echo Sounder (MBES). Improving the accuracy of your surveyed model for under keel clearance may grant the ability to increase the draft of commercial vessels. This can result in substantial financial benefits for ports.
- Areas where under keel clearance is critical.
- Areas shallower than 100 meters where under keel clearance is less critical but features of concern to surface shipping may exist.
- Areas shallower than 100 metres where under keel clearance is not considered to be an issue for the type of surface shipping expected to transit the area.
- Areas generally deeper than 100 metres where a general description of the sea floor is considered adequate.
Special Order Surveys
According to the International Hydrographic Organization (IHO) a Special Order survey is mandatory where under keel clearance is critical. This order of survey can only be achieved using a MBES.
Total Hydrographic’s Special Order Survey Experience
- Total Hydrographic own and operate an MBES capable of achieving an accuracy that satisfies IHO’s Special Order requirements
- We undergo regular professional training to ensure we are at the forefront of industry awareness
- We undertake annual under keel clearance surveys for commercial Port Authorities
It is highly recommended (and often mandatory) that under keel clearance surveys are signed off by a Certified Level 1 Hydrographic Surveyor for commercial shipping and Certified Level 2 Hydrographic Surveyor for recreational boating.
Total Hydrographic’s under keel clearance surveys are conducted exclusively by professionally recognised Level 1 and Level 2 Certified Hydrographic Surveyors, assessed by the Australasian Hydrographic Surveyors Certification Panel (AHSCP) through the Surveying & Spatial Sciences Institute.
A list of certified professionals in hydrographic surveying can be found here.
Be sure you enlist a fully certified hydrographic surveyor for your under keel clearance survey.