Chart Change

It should be quite clearly shown on a chart the position where it is required to transfer to the chart, giving the next chart’s number.

Track Consideration

As a general rule there is nothing to be gained by closely approaching a danger other than to reduce passage distance and consequently steaming time. When it does become necessary to approach a danger there are general minimum rules that need to be followed. The ship has always to remain in safe water and keep sufficiently far off a danger to minimize the possibility of grounding in the event of a machinery breakdown or navigational error.

Distance Off Danger

It is not possible to lay down hard and fast rules regarding the distance off a danger that a ship should maintain. It will depend on:

- The draught of the ship relative to the depth of water.

- The weather conditions prevailing; a strong onshore wind or the likely onset of fog or rain will need an increase in distance off.

- The direction and rate of the tidal stream or current.

- The volume of traffic.

- The age and reliability of the survey from which the information shown on the chart has been derived.

- The availability of safe water.

The following guidelines will help in determining just how far to pass off dangers.

Where the coast is steep to and offshore soundings increase quickly the minimum passing distance should be 1 ½ - 2 miles. Where the coast shelves and offshore soundings increase gradually, the track should ensure that adequate under-keel clearances are maintained. As a guideline:

· Vessel’s draught less than 3 meters – pass outside 5-meter contour.

· Vessel’s draught 3-6 meters – pass outside 10-meter contour.

· Vessel’s draught 6-10 meters – pass outside 20-meter contour.

· Vessels with a draught of more than 10 meters must ensure that there is sufficient under-keel clearance, exercising due caution within the 200 meter line.

Irrespective of the safe under-keel clearance, a ship in a situation where the nearest navigational danger is to starboard must allow sufficient distance to allow an adequate alteration of course to starboard for traffic avoidance.

Deviation from Track

Ideally the ship will follow the planned track but under certain circumstances it may be necessary to deviate from such track, e.g. having to alter for another ship. Even so, such deviation from track should be limited so that the ship does not enter areas where it may be at risk or closely approaching the margins of safety.