Runaway Scooters - Throw-behind/Throwback

[g1138]

I was sitting through a tech diving seminar at DEMA and the presenter made the comment of a scooter Throw Behind or Throwback.

That is if you have a runaway scooter you throw it over your shoulder behind you. Problem solved.
That's really all he said to the extent of it. I felt like I was the only hamster in a flock of rabbits so I decided not the ask how that method actually solves anything.


I don't operate DPV's but solutions I've heard before was, either drilling yourself into the ground, or positioning your body over the thrust to prevent forward movement until you can unclip.
Searching just now I see you can put your hand in the prop. Is that still a good idea with high powered DPV's?

The throw behind makes no sense to me for a high powered scooter.
1 it seems like you wouldn't be able to toque the scooter 180 that fast.
2 you're just going to be jerked back the other way.
3 Here buddy, catch!

Unless the presenter assumes that you're operating untethered, but then why not just let go?
Is there anything I'm missing with this method?

 

[Superlyte27]

No way I'd unclip. You now have a missile going to do God knows what, including the opportunity to impact other divers.

 

[TSandM]

I just had the opportunity to watch the PADI DPV video. They teach either allowing the scooter to run until it dies (I was taught you can run it in circles), put the nose into the sea floor or other non-fragile structure, or unclip the scooter and let it go (the last being only in an emergent situation). That goes along with what I have absorbed from friends and family who have taken other agency classes or workshops. I can't imagine how throwing a revving scooter behind you would solve anything, unless you had unclipped it first.

 

[PfcAJ]

This is why you need a scooter with a clutch. Reach in there, stop those blades. Even a fast motor gavin or suex type scooter doesn't really hurt or anything.

With an adjustable prop pitch, you can zero out the pitch so the scooter doesn't produce thrust, and with a fixed pitch on/off switch design (suex), you can turn the scooter off. With the adjustable pitch blades you can also bop the hub with your palm to de-pitch it.

In any case, there's no need to unclip the scooter, and certainly don't toss it behind you unless you want to go for an interesting ride.

 

[g1138]

I'm really really glad I'm not the only one thinking that's a bad idea.

The presentation was for NAUI.
I just checked my NAUI S&P and found that I did have the DPV Specialty page in there after all.
They do list the "Throwbehind" as a required skill.
But they also list "Controlled crashes & runaway DPV handling" as another separate requirement.

I'm going to ask the NAUI sub-forum if they have any insight.

 

[Jon Nellis]

It really depends on the scooter, but I don't recommend sticking your hand in any rotating prop. If a blade were to break before it stopped, you now have a spinning jagged edge contacting you hand.

To stop a spinning prop, I recommend feeding something into the inlet that will stop the prop for you. Kelp, tow cord, line from a reel, your buddy's fin, safety sausage, rock or anything else that you can live without.

I'm not going to turn this into an online training thread for how to deal with a runaway scooter. If some people want to reach into a spinning prop to try and stop it with their hand, I just hope their clutch is well maintained and decouples before injury. It's not my hand and I won't feel a thing. Some people lock their clutches so they will not decouple, so definitely don't do it with a borrowed scooter, unless you are sure it will decouple.

With the Genesis DPVs there are three separate ways to stop the prop from spinning. Release the ON/OFF trigger, adjust the speed knob to zero or disable the motor controller by removing the plug cover on the nose.

Every scooter is different - RTFM (... get some training from a COMPETENT instructor)

Cheers,
Jon

 

[KaizerWilhelm]

Throwing the scooter behind you will do nothing except get you tangled in the tow cord. The three ways that I was learned and teach are to stick your hand through the prop, pull the shroud to your body to stop the thrust, and to run the scoot into a hard object such as the ground or a wall, etc.

I've stuck my hand in many a prop for testing purposes and it doesn't hurt. None of the motors on scooters are strong enough to hurt you. Even the metal props out there won't do much. maybe draw a little blood if you aren't wearing gloves. Almost every scoot has a clutch, either manual or electronic, so you can't damage the scoot or yourself.

As Jon said, get training from a competent instructor.

-Will

 

[PfcAJ]

Sometimes you need to stop now (cave diving) and you won't have the luxury of finding a convenient something to shove in the prop that may or may not render your scooter permanently inoperable or allow it to get away from you.

Most stuck on scooters are fixable in the water.

 

[g1138]

Ok so Update:

Turns out Throwbehind is not intended to be used on a runaway scooter.
It is an emergency stop maneuver.

SeaCobra was kind enough to ask around the NAUI tech instructor community for me and found this answer.
There were a couple who weren't familiar with the term, but someone had an good explanation.
I think I might have either misheard or maybe the presenter fumbled over his words, but this makes a lot more sense:

To clarify: the throw behind is not used on a runaway scooter. It is an evasive maneuver primarily used in caves where you might find yourself scootering up onto a wall or something and need to stop quick.

Toss the scooter down and between your legs and get off the trigger. The scooter will act as a sea anchor. The leash is not long enough to toss over your shoulder.

 

[Knotted Lion]

Clearly a technique created by someone that has probably never been in a cave.

Ok so Update:

Turns out Throwbehind is not intended to be used on a runaway scooter.
It is an emergency stop maneuver.

SeaCobra was kind enough to ask around the NAUI tech instructor community for me and found this answer.
There were a couple who weren't familiar with the term, but someone had an good explanation.
I think I might have either misheard or maybe the presenter fumbled over his words, but this makes a lot more sense: