Grade 11 – Nautical Science

October 27, 2020

Safe water marks

Purpose. Safe water marks are used to indicate that there is navigable water all round the mark. It could be used as a centre line, mid-channel or land fall buoy, or to indicate the best point of passage under a bridge. Colours. Red with white vertical stripes are used for […]
October 27, 2020

Special marks

Purpose. To indicate to the mariner a special area or feature the nature of which is apparent from reference to a chart, sailing directions or notices to mariners. Special marks may be lettered to indicate their purpose. Uses include the following: ODAS (Ocean Data Acquisition System) buoys. Traffic separation schemes […]
October 27, 2020

New dangers

Definition. A newly discovered hazard to navigation not yet shown on the charts or included in sailing directions, nor sufficiently promulgated by notices to mariners, is termed a New Danger. The term covers naturally occurring obstructions such as sandbanks, or rocks or man-made dangers such as wrecks. Marking. Cardinal or […]
October 27, 2020

Emergency procedures and boat handling: Stopping a vessel

Factors affecting the acceleration / deceleration of a vessel Before discussing methods of stopping a vessel, we should look at the factors that affect the acceleration and deceleration of a vessel . They are the following: Inertia. Here we are talking about the amount of energy required to move an […]