Finding the up line

[TSandM]

Yesterday, we did a couple of dives off an anchored boat, where it was really quite desirable to descend and ascend on the anchor line (because of nearby boat traffic). On one dive, the line was set on the wreck we were diving, so finding it to follow it back up wasn't difficult (or wouldn't have been, had it not been moved during our dive). At any rate, we knew where to ascend by reference to the wreck.

On the other dive, there were no identifiable features in the vicinity of the anchor. The visibility was our normal Puget Sound ten to fifteen feet, and the bottom was sand with patches of kelp and anemones. I was quite worried about being able to find the line to come back up. Swimming a heading out and back is only so precise, and with limited visibility, one could be only a little way off the line and miss it completely. Our companions ran a spool from the anchor, but I've never done that. We ended up doing a pattern of swimming out from the anchor and then more or less circling, so that we would keep crossing the line.

But I'm wondering what tips people have for keeping track of, or re-finding the up line in a circumstance where there isn't a discrete structure (eg. wreck) to orient yourself upon. Is running a line the only really good option? And if so, what do you do if the anchor is in a bottom where the only tie-off is the anchor itself?

 

[PerroneFord]

I'd run a reel. If vis is really that poor, why leave it to chance.

 

[countryboy]

You can use a star pattern.. go out and back ~ 50 - 100 feet each pass..

Can cover quite a bit of ground and you are never too far from the boat / anchor.

Otherwise, as Perrone stated, run a reel off the anchor line, then you don't need to worry about it at all (even if the anchor drags).

 

[cool_hardware52]

Yesterday, we did a couple of dives off an anchored boat, where it was really quite desirable to descend and ascend on the anchor line (because of nearby boat traffic). On one dive, the line was set on the wreck we were diving, so finding it to follow it back up wasn't difficult (or wouldn't have been, had it not been moved during our dive). At any rate, we knew where to ascend by reference to the wreck.

On the other dive, there were no identifiable features in the vicinity of the anchor. The visibility was our normal Puget Sound ten to fifteen feet, and the bottom was sand with patches of kelp and anemones. I was quite worried about being able to find the line to come back up. Swimming a heading out and back is only so precise, and with limited visibility, one could be only a little way off the line and miss it completely. Our companions ran a spool from the anchor, but I've never done that. We ended up doing a pattern of swimming out from the anchor and then more or less circling, so that we would keep crossing the line.

But I'm wondering what tips people have for keeping track of, or re-finding the up line in a circumstance where there isn't a discrete structure (eg. wreck) to orient yourself upon. Is running a line the only really good option? And if so, what do you do if the anchor is in a bottom where the only tie-off is the anchor itself?

This won't work too well if you are in the middle of a flat featureless plane, but what I usually do is make a note of the depth the anchor is at. This combined with a heading usually results in being able to find the anchor on the return leg.

If you also note any current then you have a good chance of knowing if the recipical heading will leave you up current or down current of the contour that the anchor is on.

Note depth, note current, note outbound heading. If you swim back on the recipical until you reach the anchor depth you will be down current. Turn into the current and maintain the same depth and you should intersect the anchor line.

Won't work in all cases, but it will in many.

OTOH if returning the upline is critical, break out the reel.



Tobin

 

[lamont]

yup, run a line with either spool or reel to connect the anchor line to the wreck, you can also run a line around the wreck with a reel so that you have a continuous guideline back to the upline.

running line from the anchor line will also assist in running a search pattern to find the wreck as well.

which wrecks were you diving on?

 

[dbulmer]

TSandM,Lamont

Is that standard practice in your part of the world?

Over here more often than not you'd send up a DSMB.

 

[SteveAD]

attaching a decent strobe to the anchor is a bit of a help in limited vis, you can see the flash from about twice as far as you could actually see the line. should be enough if you out and back is within 20 feet

 

[tstonedvr]

Finding the anchor is the worst part of diving to me...if everybody could shoot a bag without screwing it up that would be the way to go....I did come across a Xios sonar unit that I use in bad vis that works better than great....but being as it is a machine I still get a bearing with a compass also...in your area perhaps you could run a line using degradeable hemp , that way you could forego the reeling in part...
Yarg

 

[H2Andy]

But I'm wondering what tips people have for keeping track of, or re-finding the up line in a circumstance where there isn't a discrete structure (eg. wreck) to orient yourself upon. Is running a line the only really good option? And if so, what do you do if the anchor is in a bottom where the only tie-off is the anchor itself?

if i need to run a line, i'll run it off the anchor line itself. i've only run a line a few occasions (perhaps 3 or 4?) in absolute horrid visibility. most of the time we get rather decent visibility.

i don't trust compass headings to find the anchor line in non-discreet
terrain in bad vis. you could easily miss the anchor line by a few feet and never
see it.

in low vis and flat terrain, i will keep within sight of the anchor line at all times or
run a line.

in low vis but with good structure, i will follow the structure in a predictable manner.
if i get to a landmark from which i can't continue forward with further landmarks,
i will return to the previous landmark, which will give me sight of the previous one,
and so on, back to the anchor line.

bottom line is, i need a connection to the anchor line, be it visual (direct or
through landmarks) or physical (running a reel).

i don't feel comfortable with just a compas heading. i find that these are not
precise enough to locate an anchor line in less-than-ideal conditions.

Is that standard practice in your part of the world?

Over here more often than not you'd send up a DSMB.

it is in the boats i've been in Florida, except for drif dives. once a boat
anchors, they won't leave the place until all other divers are aboard.

you could shoot a bag and come up, but you'll have to wait until they
spot you, wait for the other divers to get on-board, and come to get you.

 

[dbulmer]

Andy,
You nearly always send up a blob here particularly on drift dives but usually the skipper sees the blob ( ) and you don't have to wait too long normally. Boats with lifts are nice in that respect.