Scuba Diving Underwater Navigation 3 — Questions and Answers
Question 1: What is 'dead reckoning' in the context of underwater navigation?
- Estimating position using known starting point, heading, speed, and time (Correct answer)
- Navigating only by visual landmarks
- Returning to the surface to reorient before continuing
- Following another diver's path
Correct answer: Estimating position using known starting point, heading, speed, and time
Dead reckoning is estimating current position based on a known starting point combined with tracked heading, estimated speed (kick rate), and elapsed time.
Question 2: When planning a drift dive, where should the diver typically exit the water?
- Downstream from the entry point, at a pre-planned exit (Correct answer)
- Back at the original entry point
- At the deepest point of the dive
- Anywhere the current allows
Correct answer: Downstream from the entry point, at a pre-planned exit
Drift dives are planned so the current carries divers to a designated downstream exit point where the boat or shore exit has been arranged in advance.
Question 3: What is the purpose of a dive flag when navigating back to a boat?
- Mark the dive boat's position so divers can navigate toward it (Correct answer)
- Signal the depth the divers are at
- Indicate hazardous currents in the area
- Show the direction of the nearest shore
Correct answer: Mark the dive boat's position so divers can navigate toward it
A dive flag (or float with flag) marks the boat or entry point, giving divers a visible surface reference to navigate toward when ascending.
Question 4: What effect does low visibility have on underwater navigation?
- Reduces reliance on visual landmarks, requiring greater use of compass and tactile cues (Correct answer)
- Makes the compass spin unpredictably
- Forces divers to ascend immediately
- Has no effect on navigation technique
Correct answer: Reduces reliance on visual landmarks, requiring greater use of compass and tactile cues
Poor visibility eliminates natural landmark references, making compass navigation, guideline use, and tactile reef-following far more critical.
Question 5: What is 'piloting' as a navigation technique in scuba diving?
- Moving from one known landmark to the next in sequence (Correct answer)
- Following a compass bearing continuously
- Using a reel line from start to finish
- Ascending and descending along the anchor line
Correct answer: Moving from one known landmark to the next in sequence
Piloting is a technique where divers navigate by identifying and moving between a series of known underwater landmarks rather than relying on instruments.
Question 6: Why is it important to note the current direction at the beginning of a dive?
- To plan an into-current outbound leg so the return is easier (Correct answer)
- To select the right tank pressure for the depth
- To calculate the no-decompression limit
- To choose the correct wetsuit thickness
Correct answer: To plan an into-current outbound leg so the return is easier
Starting a dive heading into the current means the diver works hardest when fresh and has an easier, current-assisted return when air and energy are lower.
Scuba Diving Underwater Navigation 3
What is 'dead reckoning' in the context of underwater navigation?