Suspension floatation for housing

Floatation from above the rig works better for me than having bulky floats on short strobe arms which interfered with positioning. Now, even when the strobes are positioned low, the floatation is above the camera, so it is easier to hold the rig in a fairly upright position.

My camera is now neutrally buoyant and well balanced from side to side. It's nice to let go of the camera and watch it remain at your side, like a loyal dog. I think a neutral camera could also provide a useful visual reference, to help a diver maintain a constant depth, when in the blue.

The Flickr link below shows how they are attached. If you click on any of the 4 photos you can read the notes.

http://www.flickr.com/photos/pointymccracken/sets/72157634002354975/

John McCracken

I use some special, hard, closed cell foam i covered with epoxy putty to give it a hard shell around and they where zip-tied to my arms similar to the stix floats.

My rig completely neutral with the heaviest lens/port combination and when i use a lighter (more buoyant) one i just add small weights to get it neutral again.

Moving the arms back and forth i can control the tendency of the rig to tip over of heavy and/or big domes.

The hard foam don't change buoyancy between 30 and 120 ft so the rig is always neutral and this comes handy if you need both hands
for something as the camera will float on my side, except on a mooring/anchor/reef hook line with current.

Chris

My rig completely neutral with the heaviest lens/port combination and when i use a lighter (more buoyant) one i just add small weights to get it neutral again.

Moving the arms back and forth i can control the tendency of the rig to tip over of heavy and/or big domes.

Chris

Hello Chris,

Here is a link to underwatercamerastuff's DIY section where he describes a tidy way to attach small weights to a dome port. That may be a simple way to keep a rig neutral when changing setups.

http://www.uwcamerastuff.com/dyi_dome_port_weights.htm

However, I would rather add floatation to the heavier setup than add weight to the more buoyant one. I actually made two sets of floats, for two 2 different setups. That was an uneconomical use of "Divinycell". What I should have done is use clips to secure an extra layer of foam to the smaller floats. I still have some foam left, and time to kill before my next trip, so I might do that.

John

Hi john,

thanks for your reply.
Fortunately i use now only a minidome and don't need weights to trim it, but i remember my Ikelite Dome ..
Yeah, adding buoyancy is the other solution but you need to carry delicate floats but save in weight.
I approach from the other side and borrow a small ankle or else weight in the local dive shop or if not available i go
and buy some 100 grams fishing or car rim weights to add. So i have a DYS project to have fun in remote places.
after extensive use of my foam i will glue it together and make a final version of it to clamp on my 8'' arms as i am used to have it like this.

Before this solution i was thinking about a similar set-up like yours - hanging the whole rig on a float to have it most flexible in it's movements -

but for some reason (my foam came as a rather thin sheet) i ended up the arm solution.

I still believe that if the rig would be hanging on one big float attached with a swivel on the center of the housing will work very good for video as

there is almost no drag rotating and tilting the housing, but maybe it too easy to turn/tilt so the pictures may become shaky.

You may try to attach both floats on the center ball adapter usually used for the focus light to see how it works.

The back draw of my system is that i can't fold the arms all together but i am used to that so it is not a big deal for me.

Chris

Hi john,

thanks for your reply.

Fortunately i use now only a minidome and don't need weights to trim it, but i remember my Ikelite Dome ..

Yeah, adding buoyancy is the other solution but you need to carry delicate floats but save in weight.

I approach from the other side and borrow a small ankle or else weight in the local dive shop or if not available i go

and buy some 100 grams fishing or car rim weights to add. So i have a DYS project to have fun in remote places.

after extensive use of my foam i will glue it together and make a final version of it to clamp on my 8'' arms as i am used to have it like this.

Before this solution i was thinking about a similar set-up like yours - hanging the whole rig on a float to have it most flexible in it's movements -

but for some reason (my foam came as a rather thin sheet) i ended up the arm solution.

I still believe that if the rig would be hanging on one big float attached with a swivel on the center of the housing will work very good for video as

there is almost no drag rotating and tilting the housing, but maybe it too easy to turn/tilt so the pictures may become shaky.

You may try to attach both floats on the center ball adapter usually used for the focus light to see how it works.

The back draw of my system is that i can't fold the arms all together but i am used to that so it is not a big deal for me.

Chris

Hello Chris,

Earlier I said that I would rather add floatation to the heavier setup than add weight to the more buoyant one. That's how I approached it, but I suppose using a combination of weights and floats to keep the camera nicely oriented and neutral would be like having an underwater tripod.

If I were to attach all the floatation to the centre of my housing then I would have to constantly correct its tendency to tilt left side down. I haven't shot any underwater video, but if a steady hand is important then a float on either side, with some weight on the bottom dome shade, might be a good way to go.

John

Hi John,

I'm interested in some details about what tools you used to cut your foam (the cuts look extremely clean) as well as the dimensions of the 3 pieces you glued together to create each float. Somewhat similar to you, I have an Ikelite housing and a pair of Ikelite DS160 strobes I'm looking to create floats for.

A few months back, I bought a sheet of 2"x23"x24" 6lb density foam but still haven't created floats.

I really like your design as my primary use would be shooting macro and I'd prefer a design that didn't limit my ability to get as low to the bottom as possible.

Thanks!

Hi John,

 

I'm interested in some details about what tools you used to cut your foam (the cuts look extremely clean) as well as the dimensions of the 3 pieces you glued together to create each float. Somewhat similar to you, I have an Ikelite housing and a pair of Ikelite DS160 strobes I'm looking to create floats for.

 

A few months back, I bought a sheet of 2"x23"x24" 6lb density foam but still haven't created floats.

 

I really like your design as my primary use would be shooting macro and I'd prefer a design that didn't limit my ability to get as low to the bottom as possible.

 

Thanks!

Hello Jeff,

I have just added a couple of new photos, with notes, to the Flickr link in the initial post. That will give you more detail about making the cone shaped base part of the floats. After making the bases, I stacked more disks onto them to achieve the required buoyancy and balance. Initially, I attached the foam to the bases with rubber bands and took a trip to the river to get a rough idea of what was needed. Once I figured that out, I glued on the foam and did 5 more trips to check buoyancy. After each check I sanded a bit of material off with the belt sander. Eventually I got it right. One of my finished floats has three layers of 1 inch Divinycell glued onto the base part, so it is 6 inches tall and 3 5/8 in diameter. I took off too much material on the other float, so I had to add that extra nubbin to the top. To keep the right balance from side to side, the more buoyant float has to be attached to the left hand side of my rig.

These floats are neutral when I use a macro lens and port, and an attached dive light. My light, an itorch 4, is very heavy, so you may not need such big floats.

John

Thanks for the additional details!

I just checked the difference in weight between the NiMh battery and the newer Lithium batteries for the Ikelite 160 strobe. Each lithium pack weighs 800 grams less than a NiMh pack, so using the newer batteries would drastically reduce, or eliminate, the need for floatation.

It would cost me about $700 to upgrade to 2 lithium batteries and chargers, so I'll be sticking with my floats for the time being. However, if I were in the market for strobes now then I would buy new ones rather than trying to save money buying second hand strobes with the NiMh batteries. The Lithium batteries are also supposed to give more flashes per charge and a quicker recycle time.

John

Hello Anyone,

The Flickr link to initial photoset no longer works. I notice that previously working Flickr sets by tdpriest have also gone blank. Does anyone know why?

Anyway, if anyone is still interested in seeing a way to make and attach such floats, then you can click on this general link to my Flickr photo sets and select the set titled "floatation above the housing"

http://www.flickr.com/photos/pointymccracken/sets/

John McCracken

On 6/13/2013 at 2:39 AM, pointy said:

 

 

Hello Jeff,

 

I have just added a couple of new photos, with notes, to the Flickr link in the initial post. That will give you more detail about making the cone shaped base part of the floats. After making the bases, I stacked more disks onto them to achieve the required buoyancy and balance. Initially, I attached the foam to the bases with rubber bands and took a trip to the river to get a rough idea of what was needed. Once I figured that out, I glued on the foam and did 5 more trips to check buoyancy. After each check I sanded a bit of material off with the belt sander. Eventually I got it right. One of my finished floats has three layers of 1 inch Divinycell glued onto the base part, so it is 6 inches tall and 3 5/8 in diameter. I took off too much material on the other float, so I had to add that extra nubbin to the top. To keep the right balance from side to side, the more buoyant float has to be attached to the left hand side of my rig.

 

These floats are neutral when I use a macro lens and port, and an attached dive light. My light, an itorch 4, is very heavy, so you may not need such big floats.

 

John

Hi John, I know that this post of yours is dated already.  Imagine, 7 years ago.  But I like the idea of a float on top of the rig.  Couple of questions:

1. The 3 and 5/8 diameter is the largest of the Divinycell disk?  I guess you reduced the diameter by about 1/4" for each of the 5 other disks, so that the smallest would have a diameter of 2 and 3/8?

2. How does the rig hold up with a dome port?  Did you have to weigh down the dome port with tire lead weights?

Thanks in advance.