Learn to navigate both naturally and with a compass underwater.
As the author of this quoted article found out. You must learn to navigate underwater for yourself and not rely exclusively on a dive guide for underwater navigation.
This diver discovered that the hard way. He discovered it on a dive boat in Florida that didn't provide dive guides. They relied on buddy dive pairs to explore the reefs without a guide.
So it goes without saying that he got very lost underwater and eventually had a long swim back to the dive boat.
This experience prompted him to write and article describing his experience and explains how to plan your dive an dive by clues provided by underwater surroundings.
Read on for natural underwater navigation techniques.
Planning your dive
As with most things in diving, successful natural navigation begins before you even enter the water. The easiest way to interpret nature’s clues is to already be familiar with them, and to achieve that, you must know what to expect from your dive site before taking the plunge. In some instances, this may mean listening carefully to the dive briefing aboard your dive boat; in others, it may mean doing your own research and consulting dive site maps for guidance. If possible, try to sketch a basic map onto a dive slate before entering the water so that you have a reference even when other concerns (like maintaining buoyancy and checking depth and air pressure) cause you to become distracted underwater. You should make a note particularly of significant features — a reef wall, an archway, a sandy patch — and agree upon a plan with your buddy as to how you will navigate accordingly. Make sure to find out how deep these features are; otherwise, you could miss them despite swimming in the right direction. Find out about the current, too, and always plan to start your dive swimming against it so that you can return with it, assuming that your entry and exit point are the same.
Diving your plan
The first step to finding your way back to a specific point is being able to recognize it when you do. For this reason, it is important to take a moment to look around when you first descend, and make a note of standout features that will let you know you’ve returned to your entry point at the end of the dive. For obvious reasons, make sure these features are permanent, such as an oddly shaped boulder or a strange coral formation