Scuba Diving Underwater Navigation 2 — Questions and Answers
Question 1: What natural cue can divers use to determine which direction is up when disoriented?
- Watch their bubbles rise (Correct answer)
- Check their compass
- Look at sand ripple patterns
- Count their kick cycles
Correct answer: Watch their bubbles rise
Exhaled air bubbles always rise toward the surface due to buoyancy, making them a reliable reference when a diver is spatially disoriented.
Question 2: How does surge and current affect underwater compass navigation?
- It can push the diver off course, requiring heading corrections (Correct answer)
- It has no effect on compass readings
- It makes the compass spin and become unusable
- It automatically corrects the diver's path
Correct answer: It can push the diver off course, requiring heading corrections
Water movement can carry the diver sideways (current) or back and forth (surge), requiring adjustments to maintain the intended compass heading.
Question 3: What is an 'out-and-back' dive profile?
- Swimming in one direction then returning on a reciprocal bearing (Correct answer)
- Spiraling outward from the entry point
- Following a rectangular route
- A dive that starts and ends at different locations
Correct answer: Swimming in one direction then returning on a reciprocal bearing
An out-and-back profile means swimming a straight heading away from the entry point, then turning 180° and following the reciprocal heading to return.
Question 4: Which direction do sand ripples typically run relative to predominant current?
- Perpendicular to the current (Correct answer)
- Parallel to the current
- At a 45-degree angle to the current
- Ripples have no relationship to current direction
Correct answer: Perpendicular to the current
Sand ripples form perpendicular to the predominant current direction, so their orientation can reveal which way water is flowing on the bottom.
Question 5: What is a 'search pattern' used for in underwater navigation?
- Systematically cover an area to locate an object or dive site feature (Correct answer)
- Locate the ascent line at the end of a drift dive
- Navigate back to an anchor point in low visibility
- Plan the safest ascent route
Correct answer: Systematically cover an area to locate an object or dive site feature
Search patterns such as expanding square, U-pattern, or compass arc are used to methodically cover an underwater area to find a specific object.
Question 6: Why should divers avoid holding a compass near metal objects when taking a reading?
- Metal can deflect the magnetic needle causing an inaccurate heading (Correct answer)
- Metal blocks sound used by the compass
- Metal causes the compass to reset to zero
- Metal damages the compass housing underwater
Correct answer: Metal can deflect the magnetic needle causing an inaccurate heading
Ferromagnetic metals create local magnetic fields that deflect a compass needle, causing significant heading errors if the compass is held too close.
Scuba Diving Underwater Navigation 2
What natural cue can divers use to determine which direction is up when disoriented?