Negative entry vs Using a downline

[LiteHedded]

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.

it guarantees you'll hit the wreck (assuming the line is on the wreck)

 

[undrwater]

Two questions:

* My old rear inflate BC had an attachment point for a 1" crotch strap that I took advantage of. The crotch strap I purchased had rings in the front and back. The strap attached to a plastic plate in the back. Is this still considered a BP/W, or are the definitions getting fuzzy? I suppose this rig could have been pulled by a scooter, though maybe the 1" strap would have been less comfortable?

* I'm curious about managing team hot drops in low visibility. It seems it would be easy to lose sight of your buddy during a hot drop with 15' visibility or less. If you are able to maintain buddy contact during a hot drop in low visibility, what does that look like? What are the mechanics?

 

[danvolker]

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.

I am in agreement with you.....but some posters were saying they had to use a line in a good current--that a fast drift drop would not work...
And I was recalling trips I had been on in Fort Lauderdale, where alot of the captain prefer to anchor....and where some days the current will be big enough so that the diver is hanging on tight, and being spun like bait, and barely able to go down hand over hand....I"m just saying, the negative drop is just way nicer in my way of thinking....if there is no current, or little current, I would think EITHER the line or the drop is going to work fine. With no current, or low current, the captains have no need to practice hot drops, and potentially the locals in a place like this, would never have a reason to learn it....tell 10 people to do a hot drop that have never done one before, and don't show them how first, and they will probably fail badly as a group in hitting anything other than a big reef...Show them, tell them how, have a DM in the water helping with visual, and it is not so hard to get 10 divers on a hot drop that have never done it before....The crew MUST ask if there are slow descenders that have equalizing issues, and then the plan for the captain would be a special separate drop for them, where he leads them much more. You would not want a fast descender going down with the slow ones.....the large lead up current depends on the faster current in the top half of the water collumn, moving the slow descenders close to the target by the time they hit bottom--If a fast descender jumped in with them, he would be on the bottom with little current, and then would need to swim and actually need to NAVIGATE to the wreck..THIS is NOT part of Palm Beach style drift dropping

 

[MXGratefulDiver]

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.

Well, as I said earlier, on some of the dives I did earlier this week they not only can't work, they're expressly forbidden ... for good reasons involving diver safety. I understand that you can't think of it, and your responses to my earlier bullet points suggest why ... because you can't imagine what you haven't experienced. All I can suggest is that if you ever do make it to the Pacific Northwest, try to arrange some dives in Active Pass, Gulf Islands. Go ahead and do your descents the way you're suggesting. Let us know how it works for ya ... assuming you make it back, I'll be interested in hearing about your experiences.

FWIW - we weren't using a line ... we were swimming to the rocks and following the contour down.

... Bob (Grateful Diver)

 

[rivers]

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.

But my question is why not wait until slack? why do the dive when the current is still running? it is a genuine question. If conditions are tidal, doesn't it make sense to wait? I know there are places (such as Cozumel, apparently WPB as well), where the current is always running and pretty much everything is a drift.

 

[LiteHedded]

But my question is why not wait until slack? why do the dive when the current is still running? it is a genuine question. If conditions are tidal, doesn't it make sense to wait? I know there are places (such as Cozumel, apparently WPB as well), where the current is always running and pretty much everything is a drift.

you can't turn off the current on some sites.

 

[boulderjohn]

But my question is why not wait until slack? why do the dive when the current is still running? it is a genuine question. If conditions are tidal, doesn't it make sense to wait? I know there are places (such as Cozumel, apparently WPB as well), where the current is always running and pretty much everything is a drift.

First of all, conditions are not always tidal. Where I do most of my drops on wrecks, tides have almost no effect whatsoever on currents. The boats run on a schedule that pays no attention to tides whatsoever. When the captain sets out, he does not usually have any idea what the current will be like until he gets there.

 

[MXGratefulDiver]

But my question is why not wait until slack? why do the dive when the current is still running? it is a genuine question. If conditions are tidal, doesn't it make sense to wait? I know there are places (such as Cozumel, apparently WPB as well), where the current is always running and pretty much everything is a drift.

Some of our dive sites there really isn't a slack ... the water just slows down for a while and then either switches direction or just picks up speed again, depending on how the topography affects tidal shifts. I can think of a couple dive sites where a small tidal exchange is more dangerous than a larger one for that very reason ... one in particular where the standing joke is to pack your passport in case the current doesn't behave as you expect it to.

Why do those dives? Well ... because they're really spectacular. You just plan your entries, exits and contingencies accordingly. One approach definitely does not fit all situations ... and a little bit of local knowledge and adaptation to local customs makes a huge difference between having a great dive vs having an experience you'd really rather not repeat.

... Bob (Grateful Diver)

 

[rivers]

First of all, conditions are not always tidal. Where I do most of my drops on wrecks, tides have almost no effect whatsoever on currents. The boats run on a schedule that pays no attention to tides whatsoever. When the captain sets out, he does not usually have any idea what the current will be like until he gets there.

good to know. thanks

 

[danvolker]

Two questions:

* My old rear inflate BC had an attachment point for a 1" crotch strap that I took advantage of. The crotch strap I purchased had rings in the front and back. The strap attached to a plastic plate in the back. Is this still considered a BP/W, or are the definitions getting fuzzy? I suppose this rig could have been pulled by a scooter, though maybe the 1" strap would have been less comfortable?

* I'm curious about managing team hot drops in low visibility. It seems it would be easy to lose sight of your buddy during a hot drop with 15' visibility or less. If you are able to maintain buddy contact during a hot drop in low visibility, what does that look like? What are the mechanics?

First, before you jump in, you know the vis is medium, great or awful.....It it is awful, the 2 to 4 man team on the platform, jumps in at the same moment on command by Captain, and each has about 2 seconds of bubbles before they can see each other....you should all be head down vertical, and job 1 from there is forming up into a side to side group ( no leader--that can't see those behind them) , and then each getting to the comfortable descent fall and light swimming.....as it is "light pace", or even medium pace if it is a ripping current, if one diver is slightly slower than the others, it is easy to catch up and get side-to-side even, without hard swimming down....IF...If one in he group had an ear clear issue....based on the predetermined buddy or team matrix, either just the paired buddy would stop with the diver not clearing--or the team would...and this is recreational...on tech, the entire team may need to reach bottom as a unit, for the plan, in which case they all stop....but this is a recreational thread. And the "teams" are people that want the same experiences, and that want to stay together on a dive...and that have much in common with dive skills, breathing rate, swim speed, mission, etc....they don't all need to be "real" DIR's...some can be DIRish...some can just be good spearfisherman or hunters that have great peripheral awareness and a desire to stay with their friends.

So the hot drop in low vis, the group forms right after impact with the water, and keeps eye contact all the way to the bottom, and then begins the dive --side by side. Lights come in handy for signaling you want to do something.