Navigation

[RonFrank]

This happened to me too. Turns out I just had my fins on the wrong foot. :depressed: Try switching your left and right fins....hope this helps!

Very few fins have a Left or right. In fact I know of .... none....

 

[boulderjohn]

Very few fins have a Left or right. In fact I know of .... none....

But everyone has heard stories of the people who bought size large fins and then returned them to the shop, pointed at the large L's on each one, and insisted the shop had given them two left fins.

 

[nimoh]

I think it was intended as a joke, but if it wasn't, and you did have left and right fins, wouldn't the swap cause both fins to less efficient by the same amount resulting in no change of direction?

 

[gcarter]

I think it was intended as a joke, but if it wasn't, and you did have left and right fins, wouldn't the swap cause both fins to less efficient by the same amount resulting in no change of direction?

 

[boulderjohn]

This thread was very useful for a while, but it is ow showing signs of jumping the shark.

 

[4dawgma]

Obviously a joke. When did this all get so technical? Jesus, blow some bubbles and look at some fish. What ever happened to 'recreational' diving?

 

[MXGratefulDiver]

Now, a lot of people do say that it's wise to

1. look at a distinctive feature
2. take a bearing and swim towards that feature
3. Find a feature on the same bearing
4. Repeat

This way, you can find your way back easily, yeah

But now, what if you didn't want to go in a straight line?

Let's say, I see a distinctive feature in one direction, take a bearing, but see another distinctive feature once I get there, except the second one is not on the same bearing?

How would you navigate towards it and back to your entry/exit point without having to backtrack every single feature you took a bearing towards?

I'm curious about this one

In AOW class I teach a method I call "mental mapping" ... basically you establish an "out/in" line on your compass ... set the bezel ... and use it as a reference to build a "mental map" as your dive progresses. Think of your starting point as an X on that line. Before you leave the entry point, check your depth. Then look at your compass, line up the north/south arrows with the bezel markings and look at where your lubber line's pointing ... that's your "out/in" direction. Now look at where you want to go in reference to that and build a "vector" in relation to out and in. Basically, you're going either left or right of your reference line. In your head, add a line at the appropriate angle away from the "X" that designates where you started. The length of this line is determined by how far you go ... I prefer using minutes travelled to determine this. Now, each time you change headings, do the same thing and add the new "vector" to the end of the old one. You're basically building a "map" of where you're going. When you want to get back to your starting point, all you need to know is which side of the starting line you're on, and what depth you were at when you started. Swim to that depth and either turn left or right, depending on which side of the "X" your map tells you you're on. Then maintain that depth till you reach your starting point. For class, the starting point is a buoy line. For many dives it will be an anchor or mooring line. For some it may be a pier piling. But this technique will get you back there.

... Bob (Grateful Diver)

---------- Post Merged at 06:21 AM ---------- Previous Post was at 06:16 AM ----------

Did you read my post? In case you missed it, I will repeat part of it.

3. Take a compass heading on it.
4. Forget about the compass for a while and start looking at the pretty things as you head out in that general direction. Don't count kicks.
5. As you explore and gaze at the coral and the fish, keep an eye on the landmark you observed earlier.
6. Eventually get to that landmark and explore around it.​

Nowhere does I say go in a straight line. As long as you always know where that landmark is and can get to it eventually, it doesn't matter what you do on the way. You can zig zag, go in circles, go past it, whatever you want. When you get to that landmark, you know where you are and how to get back to the boat. You can explore quite a broad area while essentially going back and forth.

Use your imagination. There are other ways you can use that basic skill. For example, you might head out toward a really big landmark that is quite a ways off and do the entire dive in that area. Go wherever you want, as long as you can see it. I once led a dive in Key Largo in which we went off in a certain direction for a while until I huge coral head on my heading. I led the group in a very irregular and zig-zaggy square around it. That took almost the entire dive time. Then I got back to the landmark and followed the reciprocal heading back to the boat.

Works pretty well in clear water ... but in places where vis is typically low, visible landmarks tend to be pretty close by. Where I normally dive, 20 feet of visibility is considered a good day ...

... Bob (Grateful Diver)

 

[socaljohn]

So I'm wondering, given the results of the poll, what new divers feel they would need to take more responsibility for their navigation. Did you not get enough practice with a compass? Did you not get good information about natural navigation? Do you just not have the bandwidth to manage everything you need to do to dive, AND handle navigation? Or did no one ever make you think about what would happen, if you followed a guide to somewhere unknown and then lost them?

"re"-new diver here. I think all divers have responsibility for their navigation as you never know when you might find yourself the only one functioning or even all alone. My compass practice and natural navigation lessons were long ago. As I have my buoyancy pretty much in hand I don't feel overloaded (I elect not to complicate my diving right now with a camera) even when my buddy is leading I keep an eye on our course. We take turns leading. My caveat is that we dive mostly shore dives in Laguna. It's not like we will not find the beach but we were off his boat once at Deadman's reef and fog had come in. As we anchored pretty far from the reef and surface swam to it, when we came up it took a minute to find the boat but I knew which way the beach was. Also it is nice to swim back in underwater farther in than we swam out. My biggest hiccup with our shore diving is that I have not found charts or maps showing the reef structure underwater that I can use for planning (I will search threads and maybe start one for this). I found a couple good drawings of the Catalina dive park (no actual compass headings and a "not to scale" warning) but I look forward to using them to go between a few of the sunken vessels out there. Navigation is one of reasons I see an AOW in my future.

 

[boulderjohn]

Works pretty well in clear water ... but in places where vis is typically low, visible landmarks tend to be pretty close by. Where I normally dive, 20 feet of visibility is considered a good day ...

I'm thinking that might be why my original post said...

OK, here's one way to use a compass to explore a nice area with good visibility without obsessing on a compass dial or counting kicks.

 

[OldNSalty]

Very few fins have a Left or right. In fact I know of .... none....

As others have said-I think it was a joke but Apollo makes a left/right fin...although I think it is intended for snorkling...I recall many years ago when I would see fins advertised that had an angle cut into them so as t create the appearance of a 'V' when worn...clearly that didn't work out.