Unit 2.a.Objective and specifications of hydrographic surveysCaptain M K Barritt RN, Vice Chairman IHOCBC

“Trust in God and the Admiralty Chart”Nineteenth century hydrography and the expansion of trade

Where am I and where is my destination?

Where can I go safely?

Look for the clues on the chart

New Ships push the limits with old surveys

The US Capitol Building & Grand Princess to scale.

Pushing the margins of safety

Critical evaluation of the chart is essential“It’s in colour so it must be true!”

The importance of source data

• The mariner must be able to judge whether the information in the chart is adequate for safe navigation for his ship.

• A source diagram, supplemented by guidance in a Mariners Handbook, helps him to do this.

The importance of source data

The importance of a prioritised national survey plan

• Defined with input from the chart user.

• Reflecting agreed priorities to meet SOLAS obligations.

• Including routine re-surveys to deal with areas of unstable seabed.

• Expert committee reporting back to NHC.

SURVEY STATUSSURVEY STATUS

The importance of a prioritised national survey plan

Adequate surveys are a Governmental responsibility under SOLAS V

• Needs NHC oversight.• Needs a customer committee to help define

prioritised survey plan.• Some or all parts of the data collection and

management process can be outsourced.• IHO and its RHCs can advise.