Navigation

[BanditDJB]

I need some pointers on navigation. I dove last week and we had about 10ft vis. I admit I only have twelve dives. I followed the anchor rope down and set off in a direction following the line of my compass. I got probably 40 or 50ft from the anchor and noticed that I couldn't find my way back to the anchor (probably because I was trying to dodge a school of long Sea Nettles in my shorty). I was only at 80ft so I knew I could do a free ascent with no problem, but it would be nice to find my way back. Luckily, another diver on the same charter apeared from nowhere and I wrote to him on my slate , then he pointed me and my buddy in the right direction. I did find the anchor, but if not for him I would have had no idea where the anchor was.

I tried to notice landmarks as I swam away from the anchor but it was bridge rubble and it all looked the same. The 10ft vis was of no help either.

Next time I'm gonna wear a full wetsuit, then the jellies won't be an issue!

 

[nereas]

I need some pointers on navigation. I dove last week and we had about 10ft vis. I admit I only have twelve dives. I followed the anchor rope down and set off in a direction following the line of my compass. I got probably 40 or 50ft from the anchor and noticed that I couldn't find my way back to the anchor (probably because I was trying to dodge a school of long Sea Nettles in my shorty). I was only at 80ft so I knew I could do a free ascent with no problem, but it would be nice to find my way back. Luckily, another diver on the same charter apeared from nowhere and I wrote to him on my slate , then he pointed me and my buddy in the right direction. I did find the anchor, but if not for him I would have had no idea where the anchor was.

I tried to notice landmarks as I swam away from the anchor but it was bridge rubble and it all looked the same. The 10ft vis was of no help either.

Next time I'm gonna wear a full wetsuit, then the jellies won't be an issue!

If the conditions dictate that you must go down the anchor line, then you should go all the way down the line, until you get to the anchor. At the anchor, you should stop and adjust your buoyancy and gear, as needed, and then SET your compass to point you INTO the current.

Then you should follow your compass INTO the current for 1/3 of your air/nitrox.

When 2/3 is left, you should turn around, and return WITH the current on the reverse azimuth on your compass. This should bring you back to the anchor line.

The other possibility is to stay near the anchor all during the dive, either on the pinnacle or reef that the anchor is set, or near enough to the anchor line so that you can see it.

The main danger is getting blown down-current of the boat. Then you will have a long surface swim back to the boat, or else they will need to come get you.

And if they dont come get you, and you cant swim back to the boat against the current, then guess what? You are then lost at sea. This happens several times each year to a few unlucky people around the world. Most of them die that way. The really lucky ones get picked up by another boat.

So be careful.

 

[Richesb]

Good advice. also pay attention to the silt in the water. Watch the direction it comes from. This is a perfect indication of current. Take a compass reading - current changes direction. Look at the ripples in the sand. These too indicate current.
Landmarks / distictive rubble are a must for any distance navigating, especially as you travel in directions other than "up & back".
It is frustrating to learn and only actual experience will make you better.

Good luck, be safe, have fun.
As you were told earlier until you become "experienced & confident" stay upcurrent of the boat.

 

[Garrobo]

Well, since I get lost immediately when I enter the water, I make sure that the assigned dive 'buddy' can find our way back to the boat. That's the first question I ask him/her. If not, I ask for anoother buddy. Eliminates a lot of grief for me.

 

[ItsBruce]

A couple of useful bits:

1. Finding the anchor is easier than finding the anchor line. The anchor line is thin and easily missed in bad visibility. The anchor, while only somewhat bigger, is attached to a length of chain that is stretched over the bottom for some feet or yards. The chain is easier to find. Therefore, when you submerge, pay attention to the depth at which the anchor is set. If you are not at that depth on the way back, you won’t find the anchor. Therefore, make sure you are at the right depth when you start looking for the anchor.

2. If it is a sandy bottom, you will generally notice ridges. Those are generally parallel to the shore. Watching your angle to them will help keep you going in a consistent direction. That way you won’t have to be transfixed on your compass.

3. When you swim away from the anchor, pay attention to how long you are swimming. This can be in terms of time or the number of kicks you make or even the number of PSI of air you use. On your return, travel the same approximate distance, keeping in mind the direction and strength of the current.

4. Practice.

5. If you are in a location with strong current and there is an issue with getting back to the boat, carry a safety sausage, whistle and mirror. Practice using these.

 

[jiveturkey]

Your nav skills will get better as long as you practice. If you haven't already, invest in a SMB and practice shooting it. This way, you have something to help you on a free ascent and you can signal the boat if you drift off the line. I think it should be standard dive equipment.

 

[BanditDJB]

Hey Thanks for all of your tips. I think your all right , what I need is practice. And I'll make sure I swim up current!

 

[all4scuba05]

Depending on viz, you can spot the line more easily if you attach a strobe to it. They're not too expensive anyway. By the way, an 80' boat dive in the ocean would be one dive to have certain equipment with you. Like air powered whistle, a 6' safety sausage, mirror, strobe, and maybe even a reel. Oh, and perhaps an AOW course.

 

[Charlie99]

A couple of useful bits:
.......
3. When you swim away from the anchor, pay attention to how long you are swimming. This can be in terms of time or the number of kicks you make or even the number of PSI of air you use. On your return, travel the same approximate distance, keeping in mind the direction and strength of the current.

If in a strong current, if in doubt as to whether you will spot the anchor, ascend to the surface before you reach the anchor and boat, not after.

I learned that one the hard way.

 

[Leejnd]

Well, since I get lost immediately when I enter the water, I make sure that the assigned dive 'buddy' can find our way back to the boat. That's the first question I ask him/her. If not, I ask for anoother buddy. Eliminates a lot of grief for me.

Hmmm...the first thing I thought when I read this was, is this practice helping you to become a self-reliant diver? If you are always relying on others to be able to get you back to the boat, how will you learn to do it yourself? And what if something happened to your buddy? And do you make sure your "assigned" dive buddy is aware of your lack of navigation skills, and that you are expecting him/her to be responsible for getting you both back?

On the other hand, if you are doing this so that you can be matched up with buddies from whom you can LEARN navigation skills, then that's a good thing, as long as that's what you are doing -- using the opportunities to watch how your more skilled buddies perform nav, and asking them about it later. Because you can't expect to rely on others forever.

Just an observation.