underwater navigation

[sea_trek]

as part of a recent certification course, I learned the basics of navigation, using a compas, using a simple pattern such as square pattern or a straight line and then the reciprocal, etc. During a recent reef dive at a depth of 30 ft (my first without an instructor), I stuck to very basic pattern usually just out and back from the anchor line and did not go very far from the anchor line, to avoid getting lost/disoriented. I find that it is a bit limiting in terms of exploring the reef. I am curious as to how some of the more experienced divers seem to get right back to a boat's anchor line after 45 minutes of exploring a reef, especially when it seems that many divers are not really paying much attention to their compas. I ask this because when I went on dives with instructors, we always seemed to go all over the reef, and after 10-15 minutes or so of exploring I would loose track of the turns and different directions yet we would always come right back to the anchor line. I love diving and really want to get good at it, but this is an area where I still lack experience and confidence. Any tips/guidance is greatly appreciated.

thanks,
sea_trek

 

[all4scuba05]

That I know of most of the time they are also using terrain as a guide down there. The compass being for a general direction and reef formations for a more accurate navigation. Also the fact that some are quite familiar with the site and even skip using the compass at times.

 

[jbd]

You probably have not yet developed the big picture of the reef you are diving. You may also be paying too much attention to your compass and not quite enough to what is around you. As you go diving, learn to look for unique features along your route and where they are in relation to you. If it was on your left on the way out then it should be on your right on the way back if you are following a reciprocal course. You should be about the same distance from it each way. It takes practice to develope a global awareness of where you are.

 

[cfelliot]

I think that just what you said "experience and confidence" is the key. The instructor or DM that took you out probably has been over the same reef hundreds of times and can navigate by reference along with a compass.

I had mostly done boat dives during vacations in the past. Starting to do shore dives this summer without an instructor or DM seemed really strange at first. Slowly, my wife and I have built up confidence at several sites. We don't come to the surface as often to check our position and have become quite comfortable with our compasses.

I think it does help to have a feel for the site from previous dives.

Do an AOW course to build skills too.

 

[ReneeC]

My experience is also that "some get it, some don't"

I teach several navigation techniques including actual compass heading, patterns, minutes, kick cycles and terrain but there has to be a certain body / location / direction sense to be really good at navigation in unfamiliar locales.

I personally use the compass general direction method. I start off knowing where north and south are and then head out, accounting for current of course, into the current or across it. I may be going NNW ish for a while so I know I need to head back on a SSE ish heading to get into the general vicinityl Along the way I watch for distinquishing featuresl And i have a knack for it.

Once you learn your style it feels real good when you come back right on the boat or beach entry and all your buddies are saying "how do you do that!"

 

[jonix]

i had the same problem when i started. knowledge of the terrain is a major plus factor...i take note of "markers"... like boulders, huge clumps of coral, and other natural formations and these definitely helps my navigation. as the others said i use my compass for checking my general direction.

 

[MXGratefulDiver]

as part of a recent certification course, I learned the basics of navigation, using a compas, using a simple pattern such as square pattern or a straight line and then the reciprocal, etc. During a recent reef dive at a depth of 30 ft (my first without an instructor), I stuck to very basic pattern usually just out and back from the anchor line and did not go very far from the anchor line, to avoid getting lost/disoriented. I find that it is a bit limiting in terms of exploring the reef. I am curious as to how some of the more experienced divers seem to get right back to a boat's anchor line after 45 minutes of exploring a reef, especially when it seems that many divers are not really paying much attention to their compas. I ask this because when I went on dives with instructors, we always seemed to go all over the reef, and after 10-15 minutes or so of exploring I would loose track of the turns and different directions yet we would always come right back to the anchor line. I love diving and really want to get good at it, but this is an area where I still lack experience and confidence. Any tips/guidance is greatly appreciated.

thanks,
sea_trek

A compass is just one tool that you use for navigation ... you need to work on using them all.

Navigating underwater also requires you to monitor your depth, your direction, your travel speed, now long it takes you to get from point to point, and how long you've stopped when you stop to look at something. Also make sure you noted the bottom depth at the anchor line when you descended. As you travel, you will also want to take note of any visible landmarks, such as sunken boats, pilings, or other objects that may be noticeable on your return.

Using that information you build a little mental "map" in your head of where you are relative to where you started. What this "map" is going to tell you is which side of your starting point you are on at any given time ... and whether you are deeper or shallower than that starting point relative to the slope of the reef.

When you are ready to return to the anchor line, the easiest way to do it is to swim up (or down, depending on where you are) to the depth that you noted when you first descended the anchor line. Then, depending on which side of the anchor line your "map" tells you that you're on, you swim toward the anchor line.

That'll get you close enough to where you can see it in all but the poorest of visibility conditions.

... Bob (Grateful Diver)

 

[boulderjohn]

I agree that the ones you see diving around freely without referencing the compass probably know the neighborhood.

Here is one trick you could have used in the situation you describe, one that does not require any new skills.

Dive a direction for a while, and then do its reciprocal (roughly, you don't have to be 100% on line) until you are near the anchor line. Pick a new direction and repeat. Pick a new direction and repeat. Eventually you have followed a * pattern, covering the whole area.

 

[REII]

I personally use the compass general direction method. I start off knowing where north and south are and then head out, accounting for current of course, into the current or across it. I may be going NNW ish for a while so I know I need to head back on a SSE ish heading to get into the general vicinityl Along the way I watch for distinquishing featuresl And i have a knack for it.

I kind of use this method when diving an area I am familiar with like the third reef off Deerfield Beach. The reef runs north and south. I will go north on one side, then east across the reef and back south on the other side of the reef. Time yourself or count fins strokes.

I also sometimes use a 270' wreck line clipped to my anchor chain. It works, its just another thing to carry.

TOM

 

[sharkattack]

If I am not using a reel, I'll follow someone who is. I have not used a compass in a long time but have no problem doing so. Realy does you no good if the direction you want to go is perpindicular to the current. You still get blown off. We don't usually worry about where the anchor may be anyway. Surface where we surface and swim to the boat which is always close. With a reel, you always end up bach near the anchor. They do require some practice.