A beautiful morning at Old Garden

[notabob]

The classic method of dealing with current is to swim out on your course, turn and swim back on your course. You will have actually done two sides of a triangle. You then turn and swim directly into the current to your starting point.

Ah! But if you want to get to a certain location at a site that you know to be on a certain heading from the entry point, and you simply maintain that heading, you might end up carried quite a ways away from it by the current. For example, there's this neat old 6-7ft anchor in the rocks at Cathedral, apprximately on a 150 course from 20yds out from the entry rock. I know that to get to it, my course needs to be about 150. But if there's any current, I need to adjust my actual heading in order to get to it. Simply following the 150 heading in a current will get me somewhere else, downstream from the anchor. In my opinion your method would work just fine in an open space, where the bottom is fairly uniform, depth-wise. On a typical shore dive, though, the 3rd leg would end up parallel to the shore and very close to it.

The best method if your going to head out and back on the same line is to pay more attention to specific things than to the compass, using your compass only to make sure you're heading in a straight line. Then when you swim back, you use both the compass bearing as well as the natural navigation.

Very true. Ultimately, combining compass and natural navigation ends up being the best way to navigate, but familiarity with the compass and knowing how to navigate by it is still a very important skill, especially when the visibility is on the poor side and you're not familiar with the site enough to know the location of every ghost trap and boulder there. You may remember passing by a certain boulder on the way out, but if you're even no more than 10ft off on the way back on a bad vis day, you'll never see it!

-Roman.

 

[Spectre]

notabob once bubbled...
Ultimately, combining compass and natural navigation ends up being the best way to navigate, but familiarity with the compass and knowing how to navigate by it is still a very important skill,

Never said it wasn't. However the concept of adjusting your bearing to take into account a cross current is something that will no doubt get a newbie compass navigator lost beyond all belief. If you aren't familiar with strength of currents and how to adjust for them, you end up running off on a course that is completely not your intended course... Well, unless you can do some serious trig in your head and your a physics god...

Shellbird: The best things to do to get 'good' at navigation is a combination of all of these things. First, when diving sites that has some good sandy bottom, run perpendicular to the lines on the sand... That way you have the direction to the beach. Use your compass to determine which direction the beach is [e.g. when your trying to decide which way to go... west or east ]. If it starts getting deeper, than you're going the wrong way.

When you get to a rock reef, where you can't follow the lines in the sand, take careful note of the natural things around the point that you arrived at the reef. Then start off on your bearing you wish to go, and return on that reciprocal bearing back to the point where you entered the reef... then return with the lines in the sand to the beach.

If you get to that reef, and there happens to be a current... stick your nose directly into the current, take a compass bearing, and swim against the current. Turn and swim with the current back to the point you entered onto the reef.

Once you get some practicing following bearings, then start dealing with going cross current. I wouldn't concern yourself with currents at the moment... just do all your dives starting against the current and returning with the current... using natural navigation and your compass to give 3 independant methods of reference to keep your course [the stuff you remember, the compass bearing, and following the current line].

 

[dkerr]

Another key to navigation that I didn't see here is when you are shooting a heading in the water find an object in that path (preferably at the extent of the visibility) and swim to it. As you approach it you look at the compass and pick a new target. This method will negate current but of course only works if the vis is good enough to see a specific object.

 

[shellbird]

Ok, this has been great. But in my lake for instance, the bottom is very unusual, gets shallow, gets deep without rhyme or reason and at times low vis, very dark. How do you navigate in the dark? Very little current lines to follow. I guess the compass is all I would need or can rely? You guys are awesome, keep it coming.

 

[Spectre]

shellbird once bubbled...
How do you navigate in the dark? Very little current lines to follow. I guess the compass is all I would need or can rely? You guys are awesome, keep it coming.

In that case you will definately have to rely on your compass. With the lack of currents, it should be fairly simple to follow a heading and then a reciprocal heading, and you'll get practice with that in the Navigation part of your AOW class [as well as distance estimation].

Another option for dark and featureless diving is running a reel. However a reel can be a little tricky at first [you don't want to get wrapped up in it as you trail the line behind you]. If you choose the Search and Recovery dive with AOW, you'll get some practice with running reels [and shooting lift bags... another very useful skill].

Note: definately don't start playing with reels without a little bit of training or experience with a diver familiar with reel use... a little string running down around your legs can make for a less than relaxed situation!

 

[MASS-Diver]

Just wanted to add that I think I've seen that "pyramid" and I'm pretty sure it's natural, although it does have a very weird shape. While I love diving Old Garden, one thing that would really make it a top notch dive would be if the draggers didn't go over it. Once you clear the reef and get into 40' or so it's like a desert. It supposed to be a scallop bed. Everytime I've swam that far out I've found 1 or two live ones, but, the draggers get the rest (this is the area that is often cover in sand dollars). Too bad, as it would be pretty cool to have a place to do shore scallop dives.