Underwater Navigation & Dive Planning Flashcards

What are the two primary methods of underwater navigation taught in PADI training?

Answer: Natural navigation (using environmental features) and compass navigation (using a magnetic compass)

PADI teaches two primary navigation methods: natural navigation using underwater landmarks, current direction, and bottom contour; and compass navigation using a magnetic compass.

How do you calculate the reciprocal heading on a compass when navigating in a straight line?

Answer: Add 180 degrees if the heading is below 180, or subtract 180 degrees if it is 180 or above

The reciprocal (return) heading is found by adding 180 degrees if the original heading is less than 180 degrees, or subtracting 180 degrees if it is 180 degrees or greater.

What is a 'natural navigation check-in point' and how should divers use it?

Answer: A distinctive underwater landmark that divers identify to confirm their position during a dive

Natural check-in points are distinctive underwater landmarks (rock formations, coral heads, anchors) that divers identify during the dive to confirm their position and progress.

What key elements should a dive plan include?

Answer: Maximum depth, dive duration, air turnaround pressure, buddy assignments, entry/exit procedures, signals, and emergency contacts

A dive plan is a comprehensive pre-dive planning document covering all safety-critical parameters: depth, time, air management, buddy system, site-specific procedures, and emergency response.

What does the 'rule of thirds' refer to in dive air management?

Answer: Using one-third of the air supply for the outbound journey, one-third for the return, and keeping one-third in reserve

The rule of thirds is an air management principle: use one-third going in, one-third for the return, and keep one-third as an emergency reserve.

What factors should a PADI Instructor consider when selecting an appropriate dive site for student training?

Answer: Conditions (current, visibility, temperature), entry/exit safety, presence of hazards, depth appropriate for training level, and proximity to emergency services

Site selection for student training requires evaluating multiple safety and pedagogical factors: environmental conditions, physical hazards, appropriate depth, emergency access, and alignment with the students' training level.