Negative entry vs Using a downline

[Diver0001]

Or you could make sure you're diving from a boat that has a prop guard.

If your dive requires that you make a choice between an increased risk of drowning or an increased risk of being meat-grindered, you might want to reconsider the dive parameters.

flots

Good point. Not always practical, though.

I'll admit that Zodiacs are the only thing in diving that scare me. I've just seen some horrible things happen with them. One in Egypt I can remember where the Zodiac hit a big wave and flipped over (probably avoidable but it happened anyway), throwing everyone into the water... except the guy who landed on the prop.

When diving from a boat I prefer it to be jet-drive or at least anchored. Zodiacs, in that sense, are a necessary evil in some places but I don't like being on the surface around them.

I know it's just me. Thought I'd come clean with that.

R..

 

[jadairiii]

2) Zodiacs, being what they are, have at least one high-powered motor and as such are meat grinders just waiting for the one diver who didn't descend fast enough so that arms, legs and heads can be chopped open (or off) by some little mistake. Zodiacs are 1000 times more dangerous to divers than most aggressive sharks. The only way to be safe around a zodiac is to (a) get the hell underwater where you're safe from the propeller and (b) never *ever* ascent near a zodiac without using a blob.

R..

When diving from any motorized boat the "captain" should kill the engine upon drops and pickups. No exceptions. The divers should also drop with a float (ball/flag float/torpedo float) so that the boat knows the location of the divers. Lose the group then you need to shot a marker.

I have done this on 30' reef dives and 260' mix dives with scooters. Zodiac or a 40' cattle boat, same procedure. This is not brain surgery.

 

[Diver0001]

When diving from any motorized boat the "captain" should kill the engine upon drops and pickups. No exceptions. The divers should also drop with a float (ball/flag float/torpedo float) so that the boat knows the location of the divers. Lose the group then you need to shot a marker.

I have done this on 30' reef dives and 260' mix dives with scooters. Zodiac or a 40' cattle boat, same procedure. This is not brain surgery.

The operative word here being "should".

Here's another nice word that I'll use in a sentence for you. "Almost".

It almost always happens as it "should"

R..

 

[boulderjohn]

The divers should also drop with a float (ball/flag float/torpedo float) so that the boat knows the location of the divers.

There are many places in the world where that is not done, and for good reason. In fact, I would guess that in my experience, the ratio is about 10-1 (or more) against doing it that way.

Just because the conditions in one part of the world make a practice sensible, it does not mean it will be sensible in all parts of the world.

 

[Greenjuice]

The operative word here being "should".

There are many places in the world where that is not done, and for good reason. In fact, I would guess that in my experience, the ratio is about 10-1 (or more) against doing it that way.

An example here would be a typical Red Sea liveaboard to The Brothers or Daedalus.

Standard practice is negative entry backrolls in groups of 6 or so from RIBs. At the moment of timed backroll, the driver guns the motor in reverse and pulls backwards away.

(once, I witnessed, reversing in the direction of another zodiac that had just dropped its divers!)


Sent from my iPhone using Tapatalk

 

[jadairiii]

The operative word here being "should".

Here's another nice word that I'll use in a sentence for you. "Almost".

It almost always happens as it "should"

R..

The operative word(s) are "no exception". If I find myself on a boat that may not, I tell them too, if they don't I find a new boat.

There are many places in the world where that is not done, and for good reason. In fact, I would guess that in my experience, the ratio is about 10-1 (or more) against doing it that way.

Just because the conditions in one part of the world make a practice sensible, it does not mean it will be sensible in all parts of the world...

As to the belief that a float wont work in "some areas", bring your own, a torpedo float deflates and a cave reel packs easy. Never had a boat say I cant use it. Cant figure a "condition" that a torpedo float would not work? Used them in screaming currents, deep, shallow, with scooters, without, free diving, scuba?

 

[Diver0001]

The operative word(s) are "no exception". If I find myself on a boat that may not, I tell them too, if they don't I find a new boat.

Dream on.

I'm guessing you don't travel much, if at all.

R..

 

[danvolker]

There are many places in the world where that is not done, and for good reason. In fact, I would guess that in my experience, the ratio is about 10-1 (or more) against doing it that way.

Just because the conditions in one part of the world make a practice sensible, it does not mean it will be sensible in all parts of the world.

When I dove Catalina, with the Kelp, I had no desire or belief that my torpedo float would be viable.....But beyond the constant entanglement issue of kelp, in most other places I would consider traveling to....
If I was to travel to someplace with GREAT Diving....a place people would dream about diving....Please give me some of the scenarios/Destinations where towing the Torpedo float would be bad--that there would be good reasons for not doing it....I would hate to think that the big reason, was just that no one has ever tried it there before

I am "asking" this honestly, and NOT trying to attack anyone.

 

[maniago]

When I dove Catalina, with the Kelp, I had no desire or belief that my torpedo float would be viable.....But beyond the constant entanglement issue of kelp, in most other places I would consider traveling to....
If I was to travel to someplace with GREAT Diving....a place people would dream about diving....Please give me some of the scenarios/Destinations where towing the Torpedo float would be bad--that there would be good reasons for not doing it....I would hate to think that the big reason, was just that no one has ever tried it there before

I am "asking" this honestly, and NOT trying to attack anyone.

Similarly, I'd like to hear just what conditions towing a torpedo is good for. I've never seen it done and can't quite grasp doing it in any kind of current - even with 200' of line on my SMB, if theres a current, it goes horizontal long before reaching the surface (deployment depth depending of course)

So hows this done?

 

[danvolker]

Similarly, I'd like to hear just what conditions towing a torpedo is good for. I've never seen it done and can't quite grasp doing it in any kind of current - even with 200' of line on my SMB, if theres a current, it goes horizontal long before reaching the surface (deployment depth depending of course)

So hows this done?

Ok, thanks for the honest question.....
See the float....Riffe Torpedo Float


You normally want to use a cave reel to tow with, but there is one more key alteration to use these...they were originally intended to be attached to fish on a spear....so they don't come optimized for diving.
What you need to do is to have the cave line attach to a point about 1/3 of the way back from the nose, under the torpedo....this was, when you are 100 feet down, or 200 feet down in a current, and the torpedo is behind you with a 20 to 60 degree angle in the line--whatever you let out, and the response with swimming or current.....the line is going to pull down on the torpedo, and you DO NOT want the nose of the torpedo to be pulled straight down---you want the downward force to be averaged along the "keel" of the torpedo......but also in the front 1/3 area, so it tracks straight with you and does not turn any way it wants to.

We can be on a 100 foot dive in a screaming current, and with the thin cave line, the pull is negligible....where-as the typical dive float and yellow polypropylene line would be pulling you so hard it can be like water skiing on the bottom.
On some of our more major tech excursions to 280ft off of Palm Beach, we would use scooters, and the strongest scooter would be the one towing the torpedo....with all the huge amount of line out on a dive like this, there is some pull on the line I did not enjoy having to pull through out a swimming tech dive at 280ft--but with the scooter it is a non-issue. And again, for 130 or less, there is very little effort---and you can have a hook on the cave reel, so you can hook off if you get to an interesting area along a multi-mile long drift dive..as many times as this happens. For u/w video, it is better to be able to hook off and be absolutely unencumbered, and to not get any jerks that could show up as "Shake" in the video.

And..as to the effort of towing and how slight this really is....take a float like this on a cave reel.....and with the dive boat going full speed say 20 mph.....toss the torpedo off the back with about 20 feet of line paid out....the torpedo flies along the surface, and is easy to hold onto.....Try this with a dive flag and yellow line--and someone else better be holding you, because you could get yanked right off the back of the boat the instant it hits the water--
The streamlining of the torpedo makes all the difference. This allows us to do drift dives where between the current and our swimming, we can cover MANY miles of reefs on a single dive....and even FIND wrecks no one knew were there before ( as in patch reef areas not frequently dived on ).

[video=youtube_share;_-UIObxXIfU]http://youtu.be/_-UIObxXIfU[/video]
Shallow pretty reef you would drift with a torpedo float ( pulled by my scooter in this case) We covered about a mile, and the boat comes to us when we surface, no matter how far this is from the start point.



[video=youtube_share;GH7_q5ACzXA]http://youtu.be/GH7_q5ACzXA[/video]

Juno Reef with a bunch of other divers....a DM was towing the float.
This is a dive where you are going more than a mile, pretty much every time you do this dive And that's a '"good thing ".