Seeking suggestions on trying to video record an SMB blowing up as it ascends

[Wookie]

@Wookie WAT. If you wanna get rid of it, send it my way. I want one, but I don't want to spend the 175 pounds plus international shipping.

It’s pretty old, but it’s been well kept. Send me a dm and that will remind me to go find it. Probably in my tech tub.

 

[wetb4igetinthewater]

I need to think of something that would explode in spectacular fashion, but be easily cleaned up. I pick up trash all the time when diving, so I certainly don't want to litter as part of this experiment.

 

[Boarderguy]

I need to think of something that would explode in spectacular fashion, but be easily cleaned up. I pick up trash all the time when diving, so I certainly don't want to litter as part of this experiment.

Figure out a way to bottle feelings and I'm sure that we could pressure them into exploding

 

[BoundForElsewhere]

Hmm. If you can deploy near a boat or something submerged you could use the gopro suction mount. The surface would have to be shiny, though.

 

[rmssetc]

Actually I have an idea. Have a diver at the bottom letting up line slowly while I ascend with it filming.

Yep. Maybe with a safety diver so that if the person filming (cinematographer? videoist? filmmaker? shooter? What is the right description for this endeavor? Ah, yes, the "autuer"!) is thoroughly engrossed with the image in their viewfinder, they don't ascend too quickly or go directly to the surface.

 

[rmssetc]

There's been a bunch of talk about DSMBs lately and it got me thinking. We all know SMBs are worthless (hurry up and inflate before the boat runs you over). I figure for the sake of science that I should do a Boyle's law experiment. Get negative at depth (say 30 meters), fully inflate the SMB (attached to a spool), and then let go. I have two SMBs from before I knew better, and this is the best use of them that I can think of.

I'm seeking recommendations on how to film this with my GoPro. I'll probably DIY some sort of harness/rig and test it with regular DSMBs. It needs to hang on long enough to capture the rupture of the SMB.

Here goes, with the McScubaGuyver solution:

From the surface down, we have:

• two buoys (note -- there should be a rigid spacer between them)
• two lines running to anchors. The anchors should be the same distance apart as the spacer between the buoys
• between the 2 lines is a rigid structure, maybe 18" across (possibly an old aluminum frame from an external-frame backpack, or PVC piping). This is the camera platform, and is loosely attached to the lines so that it can ascend.
• the camera platform has multiple cameras, and possibly video lights
• at the top of the camera platform is a DSMB, properly inflated for the depth
• at the bottom of the camera platform is a short line (8 ~10') running to the bottom of the sacrificial SMB
• the diver holding the SMB is about 4 ~ 5' away from the anchors (1/2 the distance of the line between the SMB and the camera platform)
• the diver is anchored to the bottom -- between the anchor & the diver's weights, he (what woman would be foolish enough to do this kind of thing "for science"?) should be about 30lb negative
• the diver releases the SMB, allowing it to ascend gradually so that it doesn't 'overtake' the DSMB on the camera platform

The idea here is to have cameras at a consistent distance/angle from the SMB, be able to retrieve the cameras, and keep the cameras from rotating and putting the SMB out of the shot.

 

[wetb4igetinthewater]

Here goes, with the McScubaGuyver solution:
View attachment 753663


From the surface down, we have:

• two buoys (note -- there should be a rigid spacer between them)
• two lines running to anchors. The anchors should be the same distance apart as the spacer between the buoys
• between the 2 lines is a rigid structure, maybe 18" across (possibly an old aluminum frame from an external-frame backpack, or PVC piping). This is the camera platform, and is loosely attached to the lines so that it can ascend.
• the camera platform has multiple cameras, and possibly video lights
• at the top of the camera platform is a DSMB, properly inflated for the depth
• at the bottom of the camera platform is a short line (8 ~10') running to the bottom of the sacrificial SMB
• the diver holding the SMB is about 4 ~ 5' away from the anchors (1/2 the distance of the line between the SMB and the camera platform)
• the diver is anchored to the bottom -- between the anchor & the diver's weights, he (what woman would be foolish enough to do this kind of thing "for science"?) should be about 30lb negative
• the diver releases the SMB, allowing it to ascend gradually so that it doesn't 'overtake' the DSMB on the camera platform

The idea here is to have cameras at a consistent distance/angle from the SMB, be able to retrieve the cameras, and keep the cameras from rotating and putting the SMB out of the shot.

I like it!

Now fortunately I have two SMBs so I will sacrifice one to see if it explodes in glorious fashion or is anti-climactic. If the former, then I'll continue with figuring out how to best capture it.

 

[johndiver999]

Just figure out the buoyancy of the smb. Attach about 2 lbs less than the lift of the smb. Fill it up on the bottom, and then just ascend with it in your hand and film with a go pro on your head. You won't get too far and then you will have a quick test of how fast you can clear your ears. The whole idea sounds pretty boring.

I always thought it would be fun to put a bunch of air in a 2 liter soda bottle, put the cap on and send it up .. with the hope that it explodes at the surface and near enough to the boat to scare the heck out of the captain. That sounds like more fun.

 

[wetb4igetinthewater]

how fast you can clear your ears.

On ascent?!? Did you understand what I'm trying to do?

 

[johndiver999]

On ascent?!? Did you understand what I'm trying to do?

After it pops, you can test your ears... or drop it and then swim down and recover the lead and ruined smb.