MARKING ABORT POINTS - Abhishek Sabharwal

Overhere we will learn the correct procedure for marking of abort points on the chart while preparing a passage......This again seems to be a topic which is of concern , as many people onboard are unaware of the correct thing.

DEFINING AN ABORT POINT :

An abort point or a point of no return , is a point beyond which the vessel is bound to follow a passage and there is no way to look back.This might be because of  factors like , converging of land somewhere along the passage of the vessel which might severely restrict the manoeuvrability of the  vessel to turn back because of very less room and thereby insist her to proceed in the direction of the traffic flow.

HOW TO DECIDE WHERE TO MARK AN ABORT POINT ALONG THE PASSAGE :

The governing factor for determining the location of the abort point is the turning circle of the ship.
From your vessels manoeuvring diagram , determine the value of advance / transfer.

Assuming that the values as obtained by you are
Advance: 0.40 nm.
Transfer: 0.65 nm.

Please find the sketch below to understand better......

Additionally please understand that as a good practise of seamanship and as an important thing by virtue is to always try out engines ,well before the abort point so as the navigator is sure that his engines are working in good order.

Note :
Some people have the misconception , that only one abort point can be marked in a passage,which is a wrong thought.
It is possible that vessels along their passage might encounter narrow passages at more than one occasions and as a good and essential practise it is required to mark an abort point and additional actions and precautions taken accordingly.