Cognative Mapping

I have been diving since 1982 and can't remember exactly when navigating back to an ascent line became second nature. I remember the first few dives, though...man, even on defined ledges I would end up way away from the boat. I was comfortable under water but I spent more time thinking about what I was doing than where I was. Plus I was so excited about everything I was seeing that I totally spaced on where I started the dive. Unfortunately, at the time, I never had a dive buddy with more experience and my instructor failed to mention that usually a DM on board will gladly give me a tour or accompany me. This is one thing that I really stress in my classes. Especially since the DM on the boat I use is an excellent guide, very professional and one of the best divers I have ever met.

In your experiences, what do you think were the best methods you have used/learned that help you with our underwater navigation? I'd love some pointers to share with my students. When I take them on their first open water tours someone almost always asks me how I found my way back so easily.

I used the Cognative Mapping subject line because now, at almost any point during a dive, I have a good idea of where the ascent line is (if I'm using one) and generally don't intentionally pay attention to which direction I am going. I carry a compass in my BCD pocket but have not used it in years and years.

wet once bubbled...
I have been diving since 1982 and can't remember exactly when navigating back to an ascent line became second nature. I remember the first few dives, though...man, even on defined ledges I would end up way away from the boat. I was comfortable under water but I spent more time thinking about what I was doing than where I was. Plus I was so excited about everything I was seeing that I totally spaced on where I started the dive. Unfortunately, at the time, I never had a dive buddy with more experience and my instructor failed to mention that usually a DM on board will gladly give me a tour or accompany me. This is one thing that I really stress in my classes. Especially since the DM on the boat I use is an excellent guide, very professional and one of the best divers I have ever met.

In your experiences, what do you think were the best methods you have used/learned that help you with our underwater navigation? I'd love some pointers to share with my students. When I take them on their first open water tours someone almost always asks me how I found my way back so easily.

I used the Cognative Mapping subject line because now, at almost any point during a dive, I have a good idea of where the ascent line is (if I'm using one) and generally don't intentionally pay attention to which direction I am going. I carry a compass in my BCD pocket but have not used it in years and years.

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I like this topic.

The best tool I have for navigation is my watch.

The favorite technique (acutally, pretty much the only one I need) is to maintain a more or less constant speed (slow) and to look ahead and around. Looking ahead is really important if you want to swim anything like a straight line.

Other important keys to clue into to get your bearings are depth, slope and current. I'm either consciously or subconsciously aware of these 3 things at all times. As a last resort I'll look at my compass. Before I get in I set it to point to shore. For shore diving it always gives you a way to get back on your mental map.

I always take the time near the entry/exit point to find a good landmark. Yesterday, for example, I noticed a bit of rope on the bottom at the exit point. Depth was 5 meters so it was perfect. I found the rope back again for the safety stop and we stepped out *exactly* where we started. I can do this 99 times out of 100. To me this is an obvious thing to do. To the unaware it probably looks like magic

Also, look at your landmark from behind when you're swimming away from it. It *will* look different on the way back.


I could go on but I'll leave it at that for now. I'm in a hurry.

R..

I almost exclusively dive natural navigation. It's probably because the first hundred or so dives I did were all wreck dives and I developed a distrust of the compass as a result.. it's a personal character flaw ~smile~

I rely heavily on the sand. The ripples set up in the bottom by surge and/or currents are always a good clue to direction and is fairly reliable even in very low vis. At the same time, I take note of key formations in corals or orientation points on wrecks. I'm sort of carrying a mental point to point map in my head and if I know the site well enough I can usually navigate it at random using the mental image of the layout.

The only place that gets me into trouble is when I dive a site that has no distinguishing features in which case I use the timing method already described where I swim in one direction for a set period of time and then reverse the course.

Some tricks I use are to count cracks / sand traps between coral formations, track prominent corals and/or sponges, of course keeping the reef to one side or the other which is the easiest method, swim a circle around a wreck's debris field, and in the worst case I'll run a wreck reel.

Mind you, I will use a compass, I just inherently distrust it and rely on natural navigation to confirm the compass readings even when I am using it.

On a more humorous note: We had a young lady in my DM class who just could not pass the compass nav portion of the training to save herself. No matter how hard she tried, she always swam a circle. We eventually figured out that being rather well endowed taken together with the way she held her compass was causing the compass to keep pointing to the underwire support in her bathing suit. She lost her bathing suit and went commando in the wet suit on her next dive and passed the course. We teased her for months about it.

~smile~

If swimming at a right angle to a current, I always make sure to angle myself "into" it as I go. For "there and back again" dives it will minimize how much you drift away fgrom your starting point.

Like you, my best tip would be dive dive dive

At some point, it became second nature for me as well.

Scott

I think with experience navigation just becomes part of your general situational awareness.

As for specific navigation methods, I use what is appropriate at the time. Over featureless bottom in low viz, I'll follow a compass heading although it takes practice to do to precisely. On a wall or sloping shore I will navigate by terrain and depth and reference the sand ripples on the bottom. I will also back this up with a general compass heading back to the shore or wall dialed on the compass in the event I have to ascend early and swim in mid water back to the entry point.

In some deep areas with low viz I will also use what amounts to progressive penetration in becoming familiar and exploring an area. Pretty neat to see a rather normal looking rock and know exactly where you are and how to get back to the ascent line.