Negative entry vs Using a downline

[scubadada]

We have a wreck called the Castor that some divers will opt to use a line on, because it is 110 feet deep, and they like the line for keeping their group together on ascent and at stops.... However, there is usually enough current on this wreck that pulling down the line becomes an arm workout.....you are fighting hard enough to hang on, that it is a lot like being on monkey bars.....for 100 feet. And....this hand over hand descent is slow....it will take several minutes for most divers to get down like this--whereas when we dive this wreck, the Captain drops us about 200 feet up current of it, and 30 seconds of easy swim-assisted falling later, we are on exactly the part of the wreck we want to be on...and we would see the line pulling divers a few minutes later..and they will have used up a significant amount of air getting down to the wreck that we did not....

The Castor...
[video=youtube_share;PIaXVw61qJI]http://youtu.be/PIaXVw61qJI[/video]
Whether we have 100 foot vis, or if it was after a storm and the vis was only 10 feet, this is ideally a negative entry, drift drop....whether there is current or not !

And another thing! Why in the world would you WANT to only get half of an exploring dive.....half, because at the half way point, you would have to turn around and go back the way you came--this 2nd half being wasted when you really want to spend every moment seeing more new structures....if you don't have to return the way you came to a line...if you could just go as far as you wanted, then come up where you wanted--wouldn't that be better?

I certainly do not agree with Dan on all topics but with this one I do. Hot drops on the Castor and the Boynton Beach reefs are the way to go. The diving is effortless and pays back in massive dividends. Direct descent with negative buoancy is generally the way to go with an experienced group. There is little reason, on the reefs, to collect at the surface as a group prior to descending. It is easy to find the target dive on the west or eastside of the reef once down.

 

[DandyDon]

I've seen only one descent line in Cozumel waters - on the wreck, and they're rare many other places. Depends and varies.

 

[Redshift]

As usual there isn't a one solution fits all.
Sometimes it's possible to get a line down, sometimes it's not. And divers should be able to do it both ways. Some may not be able to, they may not feel comfortable, they may not be able to equalize quickly, they may not like to do a free descent, especially if there are no visual references. And it's ok, not all divers can do all types of dives. Things just need to be discussed in advance so divers can know what to expect.

I've had to do negative entries in the Red Sea where the zodiacs were taking taking a few divers at a time and dropping them close to the reef, on the Tabarka in Scapa Flow where all divers jump one after the other and descend quickly not to miss the wreck and have to find a way in otherwise they will be taken by the current... In some marine reserves it's even illegal to drop anchor and there are no permanent shot lines...

 

[Greenjuice]

As usual there isn't a one solution fits all.
I've had to do negative entries in the Red Sea where the zodiacs were taking taking a few divers at a time and dropping them close to the reef,

I agree that it cannot be a single solution answer. At the time of pre-dive planning, it might depend on:
1. Whether or not a line was possible or permitted.
2. The size of the target
3. The strength of the current.
4. The quality if the visibility.
5. The size of the group you are trying to keep together.
6. The skill of the boat driver.
7. Number of other operators trying to do the same thing on the same site.
8. Whether you have small camera or large rig with 2 strobes (p.s. danvolker - how does your wife manage her camera rig with the negative entries?)

So on a different day at the same site, you might have a different solution.

My buddy and I love negative entries as they are fun to do, but have also experienced a handful of episodes over the years of missing the target, or had equipment issues (including mask slipping off and a lost fin!).

I have also experienced cut hands on lines and used up a lot of air on descent and ascent trying to hang on.

There are dive sites in remote parts of PNG, Indonesia and Burma (Myanmar) which are so infrequently dived that even the most experienced of boat captains can be limited in predicting what conditions prevail down there.

On a liveaboard last week at the Red Sea, where negative entries off a zodiac is normal practice, towards the end of the week with a group of experienced divers having done 3 - 4 dives a day we were at around the 16th or 17th dive of the trip. One of the group backrolled in negative with his tank switched off (it happens). Having exhaled and unable to fill his BC, it was fortunate he was strong enough to kick back up to the surface and get the zodiac driver to turn his air on, or he would have had to dump his weights and abort the dive!

IMHO, negatives can be fun and efficient, even necessary in some situations, but do reduce the margins for error.

If we are honest with ourselves, I'm sure we all accept risks and take shortcuts from time to time. Wisdom is choosing the right moment.


Sent from my iPhone using Tapatalk

 

[Storker]

As usual there isn't a one solution fits all.

</thread>

Srsly, why aren't everybody able to see this simple answer to the question?

Sometimes it's possible to get a line down, sometimes it's not. And divers should be able to do it both ways. Some may not be able to, they may not feel comfortable, they may not be able to equalize quickly, they may not like to do a free descent, especially if there are no visual references. And it's ok, not all divers can do all types of dives. Things just need to be discussed in advance so divers can know what to expect.

You're contradicting yourself here. On the one hand, "divers should be able to do it both ways", on the other hand "Some may not be able to, they may not feel comfortable, [...] And it's ok, not all divers can do all types of dives."

You've never seen a gear problem develop? Never seen a diver make it halfway and not be able to equalize? Never seen a buddy team, even using the best procedures, get separated?

IMHO, negatives [...] do reduce the margins for error.

This is a major issue for me. I may be excessively risk averse, but a buoyant entry followed by collecting myself and ensuring my buddy is close by, then descending and preferably pausing at a shallow depth for a bubble check is, IMO, an extra layer of safety without which I'd feel uncomfortable. It's not an issue of skills (I think), nor equalizing, it's all about taking it slow and making sure everything is OK. Which is why I don't do negative entries at the experience level I am right now (50-100 dives, most of which in a drysuit, independent without any guide or DM and quite a few in conditions some warm water divers would deem unacceptable, like cold (4-6C) water, low (1-5m) viz and wind up to fresh breeze). Besides, if I'm weighted correctly according to my own assessment, my initial descent requires me to exhale quite a bit, and even then I'm sinking rather slowly the first two to five meters. I have done descents in a current, but that has been with the aid of a current line: Buoyant entry from the stern, grab the current line, surface check while hanging from the current line, descend with buddy. No prob, and I don't sacrifice that extra layer of safety.

Simple fact of life: One size doesn't fit all. Corollary: negative entries don't fit all divers.


EDIT:

An advanced diver should not be forced to jump in with a bouyant BC.

I guess I'm not "advanced", then...

 

[Redshift]

You're contradicting yourself here. On the one hand, "divers should be able to do it both ways", on the other hand "Some may not be able to, they may not feel comfortable, [...] And it's ok, not all divers can do all types of dives."

Re-reading, it does look that way. I was trying to say that divers should be able to dive in a variety of situations, although not all of them can. And that's not a bad thing per se. If a diver does not like or has problems in night dives, then it shouldn't go on night dives, if a diver always needs extra time during descent, then it shouldn't go on dives where negative entries and fast descents are needed.

 

[maniago]

I have dived all over the Caribean, I have dived Fiji, and cold water sites like the Great Lakes, Catalina and Farnsworth Banks.....
There is not one single place I could imagine wanting to dive at, where the use of a line for ascents and descents is not defective ( I am excluding all under Ice dives .....I see descent/ascent lines as the domain of lazy captains that don't want to learn drift proceedures. **** We have plenty of days with zero current--and when this happens, the dives are still far superior without the nonsense of the lines.... If you had to do a wreck in 10 foot vis or less... I suppose that is an argument FOR the lines....but not a good one....

BS. Again. Dan, you blew the same BS last year on a similar thread about lines.

Despite you having dove "all over", please go dive the mid-atlantic where we anchor into the wrecks in a current. Negative entry on the stern downline to a granny line and to the anchor line to the wreck ~100+' etc, 15-50' viz. Free drops and free ascents are strictly verboten. Procedure is up and down the lines and wreck reels to and from on the wreck in marginal viz.

Don't want to do it? You don't dive. Don't like it? Too bad. But don't poopoo something you haven't done in situations that warrant these kinds of procedures.

 

[MXGratefulDiver]

As usual, Dan, you've got your blinders on and anyone who doesn't dive exactly like you is somehow deficient. It's that incredible narrow-mindedness that makes your posts both entertaining and essentially worthless.

There are places where hot-drops are the only practical way to dive. There are places where if you hot drop you'll never see the dive site. And there are places where it's basically a choice. It has far less to do with a diver's ability than it does a reasonable assessment of the conditions and the logistics of the site. In other words, basic dive planning.

The notion that someone opting to go down a line is somehow deficient is silly ... most of our wreck dives here in Puget Sound require a downline, and even when current isn't an issue you really want to follow it down visually ... because in our typical 10 feet or less of visibility, missing the wreck by 20 feet means you'll spend your whole dive kicking over flat, featureless mud wondering where in hell you are.

I recall a dive I did with Uncle Pug one time on Possession Point Ferry where we did a giant stride off the bow of his boat and hand-over-handed down the grapple line. Doing the dive any other way would've put is about a quarter mile downstream of the dive site otherwise ... with no way to get back to our boat.

As always, Dan, you base your assumptions on a very, very narrow set of parameters that work well for the region and conditions in which you dive ... without considering that you've only ever dived in a very tiny set of conditions. Hot drops work well when you've got a large target area for your dive site, and a live boat to pick you up at the end of it. When you're diving a smaller target in current ... and/or off an anchored boat that you need to get back to at the end of the dive ... it's often a foolish choice.

... Bob (Grateful Diver)

 

[maniago]

As usual, Dan, you've got your blinders on ... it's often a foolish choice.

... Bob (Grateful Diver)

(without wasting space of copying the whole thing)....

Eloquently said Bob . Not something I'm very good at....

 

[boulderjohn]

I was trying to say that divers should be able to dive in a variety of situations, although not all of them can.

There are places where hot-drops are the only practical way to dive. There are places where if you hot drop you'll never see the dive site. And there are places where it's basically a choice. It has far less to do with a diver's ability than it does a reasonable assessment of the conditions and the logistics of the site. In other words, basic dive planning.

I have done hot drops to wrecks in current. (It is commonly called "dive=bombing" where I usually do it.) I have gone down lines to those same wrecks on other occasions. As Bob said, what is best depends upon the circumstances.

First of all, let's take on the issue of ear clearing. If you are going to dive bomb a deep wreck in current, you have to drop fast. Not only do you go in negative, you are best advised to suck the air out of your BCD so you are as negative as possible, and you swim down. If you might have trouble equalizing, you don't do that dive. This is an advanced technique, and you don't even try it if you can't do it.

Next, as some have said, the skill of the captain in judging current is critical. I was once one of 4 divers planning to dive a wreck that was only about 170 feet to sand and about 150 feet to the deck, so it should not have been too difficult to find. My buddy and I dropped first and went down fast. We hit the sand with no wreck in sight. We swam for a while, resigned to a sand dive, until we blundered into the wreck, where we found the other two divers who had dropped after us. My buddy and I were back on the boat first, and the captain talked about the silly mistake the other two divers had made. They had positioned themselves for the drop but jumped in before he was ready, while he was still directly over the wreck instead of in the proper place in regard to the current. He assumed they had missed the wreck, and he was very surprised to learn that we were the ones who missed the wreck. Contrary to his best guess, there was no current, so the divers who dropped while he was directly over it found it easily, while we who followed the captain's directions perfectly were lucky to find it. I have since done that wreck 7-8 times, and every one of those times the DM has hot dropped it and tied off so that we could go down a descent line. It's nice to know that you are guaranteed to hit that wreck when you get in the water.

It isn't just the skill of the captain. In a really deep wreck, the speed at which you descend can make a real difference, and you can't expect the captain to be perfect at estimating that. I did one dive on a wreck that was about 270 feet to sand. We were assuming a hot drop, which is characteristic of that dive. The captain told us, though, that because so many people miss this wreck on a hot drop, and because we had paid so much money for our gases for the dive, he was going to give the DM one shot at it first. He successfully tied off, and once again we entered the water knowing we were going to hit the wreck. It is sure harder to pull yourself down the line in heavy current, but it beats swimming along a sandy bottom while breathing down a couple hundred dollars worth of gas.

Wrecks are not the only reason to do hot drops, and you don't have to be a technical diver to need and use that skill. If you are entering a site in current and not great visibility, and everyone floats on the surface for a while before descending, your group can become too separated to get back together under water. When I was in the Galapagos, we all did negative back roll entries simultaneously, which got us underwater and in view of each other immediately. Even if you had ear problems, that was OK, because you were all together and could adjust.

In short, hot dropping is an important skill for diving in certain circumstances. As skills go, it is mildly advanced to extremely advanced. Sometimes it is the only way to go, but often an alternative is better.