Navigation is one of the most fundamental skills of scuba diving. Knowing where you’re going and how to get back to your starting point is incredibly important. It is for this reason that PADI requires it as a skill to attain your Advanced Open Water certification. Both SSI and PADI offer specialty courses that go more in-depth into navigation than the overview given in the PADI Advanced Open Water certification. I took the underwater navigation course through SSI.
Here is what it was like:
Book Work
We learned about the most basic form of underwater navigation: natural navigation. In natural navigation, you use geographic formations, landmarks, sun and light rays, shadows, and bottom composition (the slope of the bottom, a drop-off or wall, sand vs. rock or coral, sand ripples, and reef formations) to navigate.
In the second section of the book, we learned about compasses: what a compass is and why it works, variation and deviation, the parts of a compass, how to select a quality compass, types of compasses, caring for your compass, and using your compass (taking the compass heading, keeping the compass on a level plane, arm position, body position, and plotting a return course).
In the third section of the book, we learned how to combine natural navigation with compass navigation. In the fourth section of the book, we learned about special navigation situations, like limited visibility, night diving, deep diving, beach diving, and diving with currents. The final section of the book talked about the sport of navigation.
On Land
We practiced using our compasses, setting different headings on the compass, navigating a straight line forwards and back, navigating in a square, and navigating in a triangle.
In the Water
In the water, we had very limited visibility, so we truly had to rely on our compasses for navigation. Before we started, we measured our kick cycles that it took us to travel a given distance. We took this measurement several times to determine our average.
First, we navigated in a straight line, forwards and back to the starting point, using our compasses and counting our kick cycles to ensure that we went the same distance in both directions. Next, we navigated in a square. The instructor gave us our compass headings, which we recorded on our dive slates. We set our compasses to those headings and navigated in the stated direction, counting our kick cycles. Finally, we navigated in a triangle, using the compass headings our instructor gave us to record on our dive slates and counting our kick cycles on each leg of the triangle, to ensure that we wound up back at our exact starting point.
Underwater navigation may not be the most fun of the diving specialties to take, but it is certainly one of the most essential. I would recommend it for any diver.