Negative entry vs Using a downline

[DaleC]

Lynne, I think part of the problem is internet vs real life interactions, and the way things are said in blanket statements without creating a context. Of course, people can make all sorts of personal choices, and if they work, who cares. And in real life we are mostly forming friendships and not debating minutia (I hope).
But sometimes on the net things are said in a way that invalidates other peoples choices (or appear to) and one is given the option of ignoring or responding. To me, the concern is that, if unanswered, the personal choice of others becomes conventional wisdom and I will then appear to be doing something "wrong".

A good example is the non use of air for diving, as advocated by standardized regimes. Ok, if that's a personal choice but I dive air 95% of the time and know it's a perfectly sound choice for many dives. Do I respond as such, or just keep quiet? Same with self learning vs formal education, and on this board it is a constant debate in which conventional wisdom, backed by industry invested opinions, would suggest self learning to be dangerous.

And so some debates rage on even though IRL, we probably would rather talk about the six gill we almost saw

 

[MXGratefulDiver]

Regarding the negative entry ....Whether Florida or Asia or NJ or UK.... Ocean sites :

• are water --water is the same everywhere
• either Low or No current
• Or medium to high current
• have just one dominant current
• Have a top current, a mid depth current in a different direction, and a bottom current.
• Have either a bare desert like floor of sand, and one Wreck --like an Oasis in the desert
• Or there is a large reef area to be hit anyway you like
• Or there are specific structures that require some precision in descent to reach.

If I left out anything, someone should add it here....

• Water isn't the same everywhere, unless by that you mean it's wet.
• Currents aren't the only consideration. Temperature (which determines the equipment you're using), depth, and visibility all go into determining the best entry method.
• There are many other types of current, including eddies, upwellings and downwellings that sometimes have to be considered.
• Not all dive sites are wrecks sitting in the sand somewhere. Some wrecks are half-buried on shallow reefs, scattered pieces covered in life and kelp, sloping down a boulder field, or situated wherever currents, time, and storms have left them. All of this needs to be factored into how best to approach doing the dive.
• Not all hazards you need to consider will involve the dive site and current ... I had the dubious pleasure the other day to experience for the first time a near encounter with a log raft. Bet you don't see too many of those in Florida, but in some parts of the world they're something you have to factor into the dive as a potential hazard to be dealt with. There are plenty of hazards neither you nor I have ever encountered, and wouldn't know (without local knowledge) how to deal with effectively.

Negative entries are not a good idea for many different types of diving ...

... Bob (Grateful Diver)

 

[jadairiii]

• .. ... I had the dubious pleasure the other day to experience for the first time a near encounter with a log raft.

Was the log rafted being operated by a fat hairy drunk with gold chains at 30kts with about 10 other drunks on it? If not, then you are right, we don't have that risk here in S Florida!

 

[Splitlip]

I'm a solid believer in donating the primary reg. My first BPW rig was an Oxycheq razor mounted on a DR plate with an Air II (actually an Atomic SS1) with a 40 inch hose under the right arm with a 90 degree swivel at the second stage. I only dive open water so 40 was fine.

As dived the rig I made improvements. I ditched the Air II and went with your basic inflator on a short hose. I eventually went with a (66 inch) long hose routed HOG style. Not that I really need the longer hose for open water, but it two things. I kept the hose nice and tight and trimmed. And when standing without the 2nd in my mouth, it hangs nicely on my chest. When I climb the ladder and step on the deck, I spit the reg and it doesn't crash or get in the way..

I dive a custom length hose because the 5 ft was too short. It cluttered up with my necklace and stuff on my left shoulder d-ring. I don't dive with a can light so no need for the 7 ft. If I ever get a can, I'll go to seven.

My rigs are very tight and compact. 2 lights clipped off to shoulder d-rings and secured with bike tube. 6 ft marker folded in a pocket between plate and back. Knife on the waist. Only thing kind of clunky is my reel clipped off to a ring affixed to my plate behind the right hip rather than crotch strap. It permits me to sit on the boat bench with the reel in place. Anything else goes into pockets on my suits as needed.

I presently have an 18 # wing, 30 # wing, steel plate, aluminum plate, ABS plate and conventional back pack.

i will never tell anyone (except my daughter) not to dive the more "typical" configuration, but I'll never go back. There are BC's that weigh as much as my negative buoyancy rigs that require the addition of weights to offset their inherent buoyancy.

 

[boulderjohn]

So where is the crotch strap anchored? The BP and harness. That's what's keeping it all together, and where the thrust is going. It's just spread out enough that you don't feel it.


Hook your lines around the waist strap. Same effect with a well-fitted BCD.

I really don't want to go into great detail about the difference between hooking onto a crotch strap and hooking onto a BCD in terms of distribution of force, but this is the kind of statement that shows all the other readers that you are speaking from a lack of experience. If the scooter is attached to the crotch strap, it has almost no effect on the BP/W part of the rig. The forward pull pulls at the crotch area, pulling your body forward from the hip area with some (very little) DOWNWARD pull where it is attached at the back of the backplate. There is absolutely ZERO forward pull on the BP/W. The scooter pulls your body forward, and your body pushes the BP/W forward. If it is attached to the BCD, 100% of the forward pull is on the BCD, and you have to rely on a very tight waistband to keep the BCD in place as the BCD tries to pull your body forward.

Because of the arrogant presumption that only the DIR divers are good enough and equipped to use a DPV.

Its typical DIR BS.

You are making a very common and inaccurate assumption here. What has been said is that wearing a BP/W setup, as is done by DIR divers, is the optimal way to pilot a scooter of this kind. Your inaccurate assumption is that only DIR divers use a BP/W. That is simply wrong. Lots of divers who have never even heard of DIR use a BP/W setup. When I did all my advanced trimix training on boats in south Florida, I came at it from a DIR background, but my training was not DIR. My instructor had only a vague idea what DIR was about. I met many other technical divers on boats during this training. Every single one of them was rigged at least 90% the same way as I was. Every one of them had a BP/W and long hose. Not a single one of the ones I talked to--NOT ONE--knew squat about DIR. DIR is a small subset of divers who use this configuration, and the overwhelming majority that I have met are blissfully unaware of the controversy.
............................

I teach a class on behalf of PADI that teaches many of the same concepts associated with technical diving and DIR. It is similar to GUE Fundamentals. A big difference is that we do not require specific gear. We teach the skills in whatever gear the student shows up with. Students quickly realize that if they are not using the best equipment, their ability to do certain skills is extremely compromised. The course culminates in open water dives, and students find that they are stymied in ways that aren't even part of the class. For example, we do some of the dives in water where a good light is very helpful, and the dinky lights they bought for night dives won't do very well. I am willing to lend them a powerful canister light, but we have yet to figure out a way to mount one on any of the BCDs students have brought.

I bring this up because although scootering is not part of the class, I sometimes have scooters with me, and they like to have a mini-lesson just for the fun of it. I have learned that there is no way to attach it to a BCD and make it work. What I have learned to do instead is make a cunning arrangement of weight belts that creates a crotch strap that is in no way attached to the BCD. It works pretty well--enough for them to have some fun with it. I am planning to buy a separate crotch strap so I can rig it that way more easily. Try it yourself, and you will see the difference between attachment at the crotch strap and attachment to the BCD.

 

[MXGratefulDiver]

[/LIST]
Was the log rafted being operated by a fat hairy drunk with gold chains at 30kts with about 10 other drunks on it? If not, then you are right, we don't have that risk here in S Florida!

... it was approximately a mile-long pile of logs that were enclosed in a "raft" and being towed by a massive tug from the mountainside where they were harvested down to a port where they'd be loaded onto a ship for transport. We ended our dive by surfacing in a kelp bed in about 13 feet of water only to find them moving past us at rather close range.

Here's a YouTube video showing a typical log raft in southern British Columbia ... this one's considerably smaller than the one we encountered ...

[video=youtube;wyV9OZAPflA]http://www.youtube.com/watch?v=wyV9OZAPflA[/video]

... Bob (Grateful Diver)

 

[danvolker]

• Water isn't the same everywhere, unless by that you mean it's wet.

I swear some of the posters in this thread think their water is entirely different. In Fiji, it might be less dense, but that does not change our diving...

• Currents aren't the only consideration. Temperature (which determines the equipment you're using), depth, and visibility all go into determining the best entry method.

Bob, you have to know I am aware of these issues...We get temp ranges from 80 degrees to as low as 50, and that can be on the same dive in July, if we are talking tech. Many of the people the Palm Beach and Lauderdale/Pompano divers wear Dry suits all year....meaning the equipment issue is considered in my equation--if anything, the drysuit use is going to have you preferring the hot drop to pulling down a line in a significant current, as their is much more pull on a dry suit diver than a wet suit diver....As to depth, this is really a recreational thread...and time to reach 90 feet deep is so low with a fast drop, that in anything but a screaming current, you should almost land on a 30 by 30 structure without trying....but again, this is the Captain that is most reponsible...all we have to do is be negative and swim down vertically at a medium pace. We get bad vis days after every storm or nasty weather...often enough.....We use the same techniues in 5 foot vis....If it is less than 5 foot vis, our technique works, but I would rather be bike riding or doing something else if the vis is that bad....

• There are many other types of current, including eddies, upwellings and downwellings that sometimes have to be considered.

Don't know if you are being humourous or patronizing...or just trying to make sure all the bases are covered...( we'll go with that one).....In south Florida we get eddies from the Gulf Stream constantly...BIG Eddies. We don't get the huge down currents that can occur on some walls.....which I have experienced......and the trick with these is to know you are in a place that could have a powerful down current, and if it begins suddenly, to swim out away from the wall the way you avoid trouble in a rip current...Though I have heard of divers that prefer the rock climbing approach up the coral wall--I don't think that would be my choice...and the Line is not a factor, unless you never let go of it from jumping off the boat

• Not all dive sites are wrecks sitting in the sand somewhere. Some wrecks are half-buried on shallow reefs, scattered pieces covered in life and kelp, sloping down a boulder field, or situated wherever currents, time, and storms have left them. All of this needs to be factored into how best to approach doing the dive.

• Pretty much the same here and other places I have been diving...don't see a new pattern yet I am unfamiliar with--where the "water" is not really like "water"

• Not all hazards you need to consider will involve the dive site and current ... I had the dubious pleasure the other day to experience for the first time a near encounter with a log raft. Bet you don't see too many of those in Florida, but in some parts of the world they're something you have to factor into the dive as a potential hazard to be dealt with. There are plenty of hazards neither you nor I have ever encountered, and wouldn't know (without local knowledge) how to deal with effectively.

We don't see log rafts in Palm Beach....we do see drunks driving 30 foot boats, and drunks driving 90 foot yachts right over the top of reef lines, and even on a few occasions, a drunk on a yacht letting autopilot run the yacht down a 60 foot reefline.....Since we have to expect this "could" happen in ANY ascent we make, what we do on the top 20 feet of the ascent is important. One of our solutions is having our charter captain follow us, and play "chicken" with any encroaching boats if need be.....While this usually works, you clearly can't be certain your boat is near you, and not near some macro shooters that are 400 yards from where your group is...and you ABSOLUTELY have to assume that any boater in the vicinity will run right over your flag, as if it was not there....so where my group does a final stop at 10 feet, after I listen and no longer hear any doppler shift of boats and props, I make a beeline to the surface from 10 feet with a negative wing....doing 360 spins looking for boats as I ascend....and then at surface an instant 360 scan--if no boats, then I waive every one up--and they will know it is safe if I am not right back down....If I see a boat, I jackknife, and am back to 10 or 20 feet in an instant. Just like freediving. I don't like your log raft threat any better than our drunken boaters, and I would welcome a different or better solution from you on how to protect from this. Anchoring is not a done deal safe scenario, with the drunks on autopilot, your anchored boat could be a new wreck on the bottom!!!

Negative entries are not a good idea for many different types of diving ...

... Bob (Grateful Diver)

I know you honestly believe that, and all I can try to do is to find an ideal example place where the thinking is drift drops can't work....and if other than that, the area sounds like it would be FUN to dive....I will need to plan a trip there.

---------- Post added April 11th, 2014 at 12:43 PM ----------

Regarding the DIR ideas for Team....in recreational dives, TEAM does not imply what TC and a few others assume it does....
I can go out on a boat like Narcosis or Wet Temptations, or Splashdown.....and Sandra, Bill and I can be "teamed up" with a DM like Chris from Narcosis, and 1 or 2 spearfisherman that essentially want to do about what we want to do---each of us in this team or group of 4 to 6 divers, wants to swim at about the same pace( this is the pace each of us swims at naturally), each has very similar things we are looking for on the dive, and each understands there will be some photos taken, and some waiting when this is happening....Everyone in this team will agree to keep each other in peripheral awareness, so we are all in contact with each other throughout the dive, and will also be ascending and surfacing in a group together ( expected for boat pickups). Some of the spearfisherman are awesome divers, a DM like Chris is a bulletproof diver....but they are not DIR...some will wear traditional BC's....but they all want to do the same thing, and they can all agree on how to do the dive together...that is "Team".....It does not get crazy strict untill you get to the tech stuff, where the gear that works well at 220 or more, is much more specialized--and the training is less common for this depth, so you just can't pick 3 other people off any charter boat, and ask them to go with you down to the 220 foot wreck or reef....

For recreational dives, DIR guys will dive with non-DIRs all the time in Florida....Most other places too I would expect, which is why this thread is so troubling---I don't know where this animosity for DIR divers is coming from....Look at the way the DIRs on this thread are talking, and look at the downright hatred and Mike Tyson Bad Intentions coming from some of the non-DIR's...So who is becoming a caricature ?

 

[rivers]

Why on earth would anyone go down a line in significant current? Unless we are on a drift dive, we dive at slack tide. The current is sometimes still running slightly on descent, but no one is hanging on the shot line like a flag in the wind on descent. Normally it's a thumb and middle finger forming an 'o' around the line, which is followed down to the wreck. If the wreck isn't permanently shotted (and most aren't, unless they're in a harbour or bay), once the last team hits the bottom, they send the shot line back up to be recovered by the boat crew. At the end of the dive, pop your blob and it's a green water ascent to the surface where the boat will recover you.

 

[Splitlip]

I know for a fact that Dan dives with non DIR divers. I am not DIR although my rigs are pretty much Hogarthian these days. Dan knows I often dive splits (bad knee from a ski accident) The only thing he has ever said to about that was to offer me the opportunity to dive a soft pair of his Dive-R fins. Haven't taken him up on it, but maybe this summer.

 

[boulderjohn]

Why on earth would anyone go down a line in significant current? Unless we are on a drift dive, we dive at slack tide. The current is sometimes still running slightly on descent, but no one is hanging on the shot line like a flag in the wind on descent. Normally it's a thumb and middle finger forming an 'o' around the line, which is followed down to the wreck. If the wreck isn't permanently shotted (and most aren't, unless they're in a harbour or bay), once the last team hits the bottom, they send the shot line back up to be recovered by the boat crew. At the end of the dive, pop your blob and it's a green water ascent to the surface where the boat will recover you.

Good to know you routinely dive in an environment where that approach works for you. Those of us who dive in other parts of the world are envious.