Q: Will current NATO testing
of GPS blocking affect the mapping and therefore the results of
Q: I saw on a local news page that GPS signals will be unreliable along parts of the North Carolina coast due to military tests from the 11th through the 20th of June, and I wonder if this will affect operations, and if so, could you comment on what it is like reverting to older methods of navigation like sextants? Does anybody on board even have a sextant anymore?
A: We use GPS navigation for practically everything we do. Not only is it used for the ship's navigation, we also use it for tracking the submersible, marking collection locations, and determining our next dive sites. Captain Ralph had been notified of the unreliable GPS navigation off the coast of the Carolinas through a navigation alert system.
This will definitely impact the accuracy of our data, and may mean that we have to look harder for some of our target sites. If our dive sites are more than 150 nautical miles off the coast the tests will not affect us however.
We do have a sextant on board, but we don't plan to use it. Our
understanding is that the GPS system will continue to work, but
will not give as good a resolution as under normal conditions.
For example, if we can find a location to within a meter square
when the GPS is fully functional, we can get within a 10 meter
square when it is degraded. The captain does know how to use a
sextant if there were an emergency that forced us to abandon ship
(which is unlikely, though we are prepared).