Here is the Question, dealing with Helium and Balloons....

[Fishkiller]

Alrighty with the murky lake waters around here, in between the miles of beaches, are warm enough for me, Zellet had been ready to finally get certified and Together on his first dive as a Certified Jr Diver want to launch several Helium filled balloons from about minus 30 feet...

Planning so far:
Found a one time use Balloon Helium container, cost 25$

Found balloons and Glow sticks for a possible evening launch, Can you say UFO

Found the need for a video camera to video tape the balloons leaving the surface of the water.

Now this is where the question comes to play, I guess it really boils down to doing a multiple launch or single launch, as would it be better to fill a game bag with several balloons on the surface prior to the dive and Drag the bag down, using extra lead, and release the smaller balloons while filling the much larger special balloon? or fill the balloons at depth and release as they are filled ending with the large one?


thanks

 

[Scubaroo]

Just remember that 30' is ~2ATA, so only half fill the balloons if you're filling them at depth. I'm betting you'd need a ton of weight to submerge several at once.

eg. an 8" diameter balloon (assume a sphere for ease of calculation) is about 0.155cf in volume. A cubic foot of sea water weighs about 64lb - so you would need 9.9lb of lead just to make that single balloon neutral at the surface!

I'm ignoring the negligble extra buoyancy imparted by the helium in this small volume.

 

[roakey]

You'll have to tell us how it goes. I've inflated balloons underwater before, but never helium ones.

Unless the balloon material is extremely hydrophobic or you can spray it with something that'll make it hydrophobic, I'm going to guess that they'll be enough water on the balloon, or capillary action between the balloon and the water that they'll never "take flight."

But I'm just guessing.

Roak

Ps. In the past we'd get to about 60' with small balloons, fill them up close to full and when released they'd become lack-of-depth charges.

 

[Big-t-2538]

If you can find a good way to fill them at depth and launch them with glow sticks...I want copies of the video

 

[Spectre]

Released helium ballons drift off over the ocean. When the helium leaks out, they land on the water. Sea turtles think they are food, eat 'em and die.

turtle-killer!

 

[roakey]

Spectre once bubbled...
Released helium ballons drift off over the ocean. When the helium leaks out, they land on the water. Sea turtles think they are food, eat 'em and die.

turtle-killer!

Drop the smileys, I cut up those plastic can-holders to assure no marine life gets trapped in them, so point taken.

However, I know of no sea turtles within 500 miles of Santa Rosa, New Mexico. Thankfully, this was a long time ago and I don't litter anymore.

Roak

 

[Big-t-2538]

Spec-

How do you know this isn't planned for some quarry nowhere near the ocean...

 

[Scubaroo]

Actually Spectre has a good point. Years ago we found a helium balloon on our farm with a "please write to..." tag attached to it, that had been released something like 300km away weeks before - it had been on the ground for a while when we found it. I've heard the same problem with turtles - they think they are jellyfish, and eat them. Same deal with old plastic shopping bags.

 

[Scottri]

Why not fill them with Hydrogen and then shoot them with a flaming arrow when the reach altitude? I would suggest doing it at night over a campground for full UFO affect

I won't go into the stories of me and exposives.


Scott

 

[Dectek]

Flaming arrows shot into the air above a campground?

Do you pee into the wind too?