Take 10 #4: Positioning
This issue of The Navigator has looked at positioning at sea. Here are ten points to take away from this issue to help ensure this important subject stays top of everyone’s list of priorities.
1 Aware and alert
Professional navigators need constant situational awareness to ensure the safety of lives, the vessel, her cargo, the environment and to ensure commercial effectiveness.
2 Safety in numbers
Never rely on a single means of fixing the ship’s position.
3 Check, check and check again
Good situational awareness requires the continual checking of complementary positioning systems and the intelligent application of common sense.
4 Judging the jamming risk
Although the coordinated use of multiple GNSS, such as GPS and GLONASS, improves reliability, all GNSS share a common weakness and therefore are equally susceptible to intentional or unintentional jamming.
5 Multiple choice
There are many methods of positioning available for the navigator, some based on traditional techniques and others on modern technology. Each has strengths and weakness and no one system has proven to be good enough to use on its own.
6 The Human Element
Although all these positioning methods may be complementary, they are not always automatically integrated.
The professional mariner needs to be the human integrator of these systems and this skill require training and practice.
7 Prepare for failure
The loss of GPS is a real risk, and should be identified as such, with clear procedures for identifying failure, contingency plans and drills for dealing with the loss.
8 Avoiding over-reliance
Over-reliance on GPS, particularly when integrated into ECDIS, can lead to complacency and poor decisions. The use of GPS with ECDIS has revolutionised navigation and all shipping companies and crews should assess how this impacts on navigational practices.
9 Pole positioning
Training for the use of electronic positioning systems should not just address how to use the knobs and buttons (‘knobology’), but most importantly, how to use technology to support good decisions with full awareness of inherent weaknesses.
10 Share your knowledge!
Mentoring is key. Experienced mariners should take time to help fellow mariners master positioning techniques.
This may be Masters mentoring in the use of the sextant, or juniors helping the older