Navigation

[BAMA6977]

OK, I suck at navigation!! I get so absorbed in the dive that I end up in "East a Bobo" away from the boat. Suggestions on how to improve.

 

[AfterDark]

Use your compass. Check your heading routinely, there's a lot to keep track of while you're diving. You want to enjoy the dive and part of that enjoyment is being able to end the dive in pretty much the same place you started. You don't get so absorbed in the dive that you run out of air do you? Whenever you check your air, check your heading. Do NAV drills if you need too. My console is a 3 gauge console so every time I look at it I see my air, heading and depth, all components of navigation. Air for the turnaround time/location, heading where you’re going what direction to return and if shore diving, depth, most bottom contours get shallower closer in so if you arereturning and going from 30’ to 60’ check your heading. Write the important directions on a slate example: if traveling north the shore is east.....headed out NE, turned to the west 10 mins after start...

 

[Scuba_Noob]

Try checking your compass every time you check your buddy or check your air. Maybe you're currently too task-loaded. If you're using a camera or other unnecessary tools, don't bring them until you're better at navigation. Also, you can use landmark navigation in addition to compass navigation.

Is it just an attentional problem? Or is it difficulty in reading the compass? If it's the latter, look back on your OW book for tips.

 

[DivemasterDennis]

Ways to improve navigation:
1. Practice, practice, practice. On land, in water, practice setting and reading your compass for direction, AND develop a method for keeping track of distance such as kick cycles, time, etc.
2. Believe your compass
3. Use your compass. That means referring to it more than once during a dive.
4. Combine compass with other nav techniques, such as navigating object to object.
For more detail read my blog post here on scuba board titled "Navigation for the Recreational Diver."
DivemasterDennis

 

[MXGratefulDiver]

OK, I suck at navigation!! I get so absorbed in the dive that I end up in "East a Bobo" away from the boat. Suggestions on how to improve.

First off, remember that diving's a three-dimensional activity. Your compass is just one of the tools you can use to help you navigate. You can also use your depth gauge, your bottom timer, and even your SPG. But most importantly, you can use your brain. All those tools are available, and with some practice they will all give you valuable information, depending on the dive site and profile.

I use a procedure I call "mental mapping". Before you get in the water, after the briefing, take a heading that you can establish as "out". Set your bezel and use this heading to create a mental reference line that you use as your starting point. The downline on the boat is an X on that line. When you drop down the line ... before you leave the line, take a look at your depth gauge. What's the depth at the base of the line? Bottom topography at most dive sites is relatively even and at least somewhat sloped ... so knowing the depth you want to end up at can provide useful information. Now ... again before you leave the line ... look around you. See anything you can use as a visual reference on the return? If so, make note of where it's at relative to your starting point ... on the return, knowing where your line's at in relation to other visual references can be the difference between finding the line or not.

Now, as you head away from the line look at your compass. Where are you going relative to the "out-in" reference line you set on your compass and visualize this as the beginning of a "map" you're going to create in your head as you go. Chances are you'll be going somewhat to the left or right of the reference line, and at some sort of angle. Looking at the position of the arrow on your compass relative to where you set the bezel will show you how much of an angle. Mentally draw that line away from the "X" you established as your starting point. The length will be determined by how much time you swim before you get where you're going.

If you're moving a lot, continue to append lines to that little map you're building in your head. When you're ready to get back to the boat, all you have to know is whether you're on the "left" or "right" side of the reference line you established before the dive ... and what depth you need to be at. Swim to that depth and, depending on which side of your reference line you're on, turn left or right and remain at that depth. At some point you should run into the downline. As a backup, keep the landmark(s) you noted when you first descended in mind, and if you see them you'll know you're close.

... Bob (Grateful Diver)

 

[TSandM]

A typically great post from Bob!

Navigation can range from very easy to very difficult, depending on a number of factors. Navigation in good viz is much easier than in low viz; navigation on well-defined structure is much easier than navigation on something like scattered boulder clumps. The key is to gather as much information as you can, and Bob is spot-on with saying that the first thing you need to do is study the position of the anchor. How deep is it? What kind of structure is it in? And although it can change, is the chain lying on the bottom, or at an angle up into the water column?

If there is structure, are you putting it on your right or your left as you leave the anchor? Is there current? (Although current can change, it can be a navigational aid. In addition, your timing will be different if you swim out into current and back with it -- you'll need to start looking for the anchor earlier than you think in that case.)

Is there a well-defined depth contour? In that case, you have another reference. "Uphill" on your left going out, on your right coming back.

Bottom sediments may change -- there is a local site where a change from white sand to dark gravel is a known navigational marker.

And if you're uncertain of your navigational skills and you really need to get back to the boat, consider making only small forays away from the anchor line. Go out as far as you can still see the line, and come back, and then do another "ray". (In the worst conditions, I've done this running a line!)

The hardest navigation dive I've ever done was a flat bottom with scattered boulder clumps in about 10 feet of viz. You couldn't swim a compass heading, because the clumps of structure weren't arranged in lines. You couldn't see the anchor line more than about ten feet from it, and there was no depth contour at all (total depth variation for the whole dive was about three feet!). All we could do was try to get back to the general vicinity of the boat, and plan a surface swim. That's not an option anywhere where there is significant current or wind, though.

 

[MXGratefulDiver]

The hardest navigation dive I've ever done was a flat bottom with scattered boulder clumps in about 10 feet of viz. You couldn't swim a compass heading, because the clumps of structure weren't arranged in lines. You couldn't see the anchor line more than about ten feet from it, and there was no depth contour at all (total depth variation for the whole dive was about three feet!). All we could do was try to get back to the general vicinity of the boat, and plan a surface swim. That's not an option anywhere where there is significant current or wind, though.

I remember that dive ... Hat Island, right?

They should just name that place Fugawi Reef and be done with it ...

... Bob (Grateful Diver)

 

[arthurmnev]

You can also use your depth gauge, your bottom timer, and even your SPG. But most importantly, you can use your brain. All those tools are available...... Bob (Grateful Diver)

Did you just accuse everyone of having a brain?

and with some practice they will all give you valuable information​

I have seen plenty of people that cannot produce any useful information by using their brain no matter how much practice they have

 

[tracydr]

First, always make sure your compass is completely level. Speaking if which, is there a less sensitive compass that allows slightly off level readings?
Practice in a field on land, day and night, both.
Always make sure to make a sight-line with at least one and preferably two landmarks in-line with where you're going, if at all possible. It's very, very hard to swim Or even walk a straight line without a visible target.
Finally, are you setting your bezel on the compass properly when starting? You should be setting your bezel when you start the dive so that you know which way out and back are.

---------- Post Merged at 04:58 PM ---------- Previous Post was at 04:37 PM ----------

I found this great tutorial. Very helpful to me.
http://divebetter.wordpress.com/2007/10/04/basic-skills-review-compass-navigation/

 

[Quero]

First, always make sure your compass is completely level. Speaking if which, is there a less sensitive compass that allows slightly off level readings?

Suunto SK7.