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CornishChris

Inflatable Boat Jump

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So we were discussing this last night and wondered what the story was. I have heard that they are very hard to keep stable - 2 in boat and 2 AFFing boat - but the main question is what do you do with the bioat afterwards? Does it just float off or is there a way of keeping it with you?

Anyone done one? Was it fun? things to watch out for?

Any feedback appreciated.

CJP

CJP

Gods don't kill people. People with Gods kill people

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If you are REALLY brave you can hold onto it......but most people don't. At break off have everyone do a coordinated roll out. TO THE LEFT!!! As to stay away from hackey handles. I have seen most successfull ones with 3 in the raft and 4 holding it. A coordinated exit is essential.

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"A coordinated exit is essential. "
Word.

Also a tailgate is really useful, you can haul them out of side exits, but its really, really, difficult.
Oh, and make sure you get the inflation of the thing right, otherwise it will pop on the ride up, pressure being lower at altitude and all that science stuff.....B|
--------------------

He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me. Thomas Jefferson

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It's all about the EXIT. Don't know about a boat, but a raft will fly itself once launched. It's a ring with the rafters createing a perfect arch in the middle. Make sure all the rafters exit the raft together by holding onto the rig in front of them with the front man giving the signal. Don't want to leave anyone behind. The wingmen should have already broken off and tracked away. Once cleared of the raft, have one jumper pull and follow it down. Have a ground spotter w/ a pickup and cell phone. I would'nt pull with it, can you say LINE TWISTS! Have fun and be safe!

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Probably the big expert on this is Scotty Carbone (over 130 raft jumps, lots of success). PM him for tips. B|

Safety rule one - non-negotiable - NEVER get over the raft, even video. Follow it from the side.

Rafts sizes. Put 3 in a 3-man, 4 in a 4-man. They tend to float. If you put 3 in a 4-man, it will float and no one will stay with it.

Inflation. Only inflate it half-way. Be prepared to release air at 10K.

Coordinate with the pilot. One person is in charge and communicates with the pilot. Good count. A zero-g is almost required for a 4-man.

Launchers. 3 on each side for 3-man, 4 for 4-man. One person in the back will help, but be aware that they will almost come over the top.

Ropes. Two methods. Either cut the ropes and grip a knot. Or - thread the ropes through the grommets, but (safety note) take a grip on each side of a grommet. If you grab ropes with both hands between grommets, you risk a 2-hand wrap if the raft flips.

Breakoff. Outside people track at 5. Inside people roll to their left at 4000. Roll "Left" at the same time with hands on hackeys to prevent snags.

You may or may not recover the raft.

Never get above the raft.

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Ropes. Two methods.



Another option is to tie pull-up cords on the plastic attachment points on the outside of the raft. Do not ever tie loops - too much risk of getting hands caught in them. Pull-up cords should be gripped freely by the loose end and if you can't hang on, you can't hang on - no big deal. Wait 'till it floats down and take it up again ;)

<-- One raft dive. Went to hell.
Trapped on the surface of a sphere. XKCD

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The reason that I suggested ropes (cords) is that they come with the raft. Also, they can be easily cut to length with a hook knife. A big knot is easy to grip during launch and easy to release. I haven't tried pullup cords.

Martini Shots took an excellent pic of my last one at Rantoul. Their website isn't up though.

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Coordinate with the pilot. One person is in charge and communicates with the pilot. Good count. A zero-g is almost required for a 4-man.



I have to take exception with this. I do NOT like the idea of jumpers convincing the pilot to do Zero Gs. Because what you usually get from the pilot is NEGATIVE Gs. In an Otter you can strike the tail very easily doing this. I have flown raft jumps and they NEVER needed Zero Gs to launch.

Be careful what you ask for out there. You just might get too much of it.
Chris Schindler
www.diverdriver.com
ATP/D-19012
FB #4125

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"Scotty Carbone (over 130 raft jumps, lots of success). PM him for tips."
"Carbonezone" is Scotty and Tammy's username.
:)
--------------------

He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me. Thomas Jefferson

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good advice all around on this thread.

I've done a couple raft jumps, one went well the other didnt. Basically the raft wants to be on top like a parachute, so you need to have the weight around it evenly distributed to keep it from tilting and flipping. Put some heavy people on the inside and have them keep their butts on the floor of the raft so air can't get in between.

What riddler said about loops is critical. I've seen a terrifying video of a raft that had a rope going along the sides making a "loop" with raft on one side and rope on the other side connected at two points. The raft popped and a jumper's ankle got wrapped in the now-slack rope. In what seemed like an instant the deflated raft twisted up several times putting the jumper dangling head-down from a nasty entanglement. Fortunately the jumper was able to free herself with plenty of altitude to spare... IIRC she lost a shoe tho.

moral of the story: keep the ropes short and no loops

nathaniel
My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me, Lebowski?

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Coordinate with the pilot. One person is in charge and communicates with the pilot. Good count. A zero-g is almost required for a 4-man.



I have to take exception with this. I do NOT like the idea of jumpers convincing the pilot to do Zero Gs. Because what you usually get from the pilot is NEGATIVE Gs. In an Otter you can strike the tail very easily doing this. I have flown raft jumps and they NEVER needed Zero Gs to launch.

Be careful what you ask for out there. You just might get too much of it.



I agree with you. I don't do rafts out of Otters for that reason. I was talking about tailgate a/c.

I worry about tailstrikes on Otters. Personally, I would prefer if people didn't launch rafts from Otters.

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Ya, the raft has a burble like a battleship!
Have the wingmen wear gloves too. If a hand gets wrapped just peel the glove off.



Good point about the burble. If a person is inside the raft or has their hand inside the burble, their alti will read incorrectly.

As far as gloves, I've seen ropes wrap both hands. When that happens, there is no pull time and an AAD would just launch your reserve into a spinning ball of junk.

It is better to take precautions that prevent wraps like cutting the ropes short and knotting, or grommet-side grips.

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Put some heavy people on the inside and have them keep their butts on the floor of the raft so air can't get in between.



They don't have to be heavy, but they should lean back on launch because the relative wind will try to flip the raft forward.

The launcher on the back side of the raft will be standing on his head on launch and nearly join them for a second or two. Tail-side launcher is a tough slot.

Riders should have knees together, ankles spread, leaning on each other. Lean back on launch.

After 5 seconds, the raft becomes stable and they can talk (because they are inside the burble) and goof around.

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Good point about the burble. If a person is inside the raft or has their hand inside the burble, their alti will read incorrectly.
.



How differently would the alti read?

I've done a few rodeo jumps...so obviously I was sitting inside of a burble...and used my altimeter to determine when to dismount...

how different will the alti be while in the burble?

--------------------------------------------
Elfanie
My Skydiving Page
Fly Safe - Soft Landings

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The raft is only half-inflated when boarding. We let air out on the way up because the external pressure decreases. Therefore, at around 4K on the way down, it is pretty limp.

It has the float characteristics of chopped main. They tend to spin and drift, but generally go less than a 1/4 mile when dumped at 4K. If you lose it out the door, it's heading for a different zip code.

I have seen video guys bump one with their feet in half brakes, I do not recommend this at all. It can wrap your main very easily.

At Rantoul, most of ours landed on the airport. Obviously, they can land anywhere. Houses, cars, etc. I don't put my name on it for liability reasons.

I have followed one down over a 4-lane highway. It drifted from side to side and eventually landed 100 yds from the highway. Pure luck. If you are following one down, you may chase it and then a minute later, it is chasing you. Be careful.

I've had rafts land on top of campers. A skyball will go through the roof of a camper.

You should also try using inflatable pool toys. They are easier to launch, manage, and they are less damaging when they land. Rafts are $40, pool toys are $12.

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NOTE - Rope holders should also WEAR GLOVES

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Breakoff. Outside people track at 5. Inside people roll to their left at 4000. Roll "Left" at the same time with hands on hackeys to prevent snag


Righ hand on hackey.....left hand holding lightly on the side of the persons container in front of you (covering reserve handle with the inside of the upper arm). Counting and rocking...."you can hear each other" "ready - set - roll"

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