Need Suggestion on Marine Housing Material...

Using the PVC pipe as a mandrel, make yourself some fiberglass pipe. You can buy it fabricated, but you sound like a 'hands on' fellow.

Better solution? Maybe. Lighter solution, almost certainly. More bouyant solution? Is bouyancy a problem?

Polybutylene 0.60
Polymethylpentene 0.83
Ethylene-propylene 0.86
Polypropylene 0.90-0.92

Polyethylene LDPE 0.90-0.93

VLDPE 0.79-0.85

LLDPE 0.91-0.94

HDPE 0.96-0.97

Polybutene 0.91-0.92

The above materials will all float. Bonding to polyethylene could be a problem.

Density of FRP pipe is about 1.66. lyn is correct, the plastics he gives in #3 will all float, but an open pipe of FRP will sink.

Does this enclosure need to be 1/2" thick?

I don't know what they cost but these people have what you need, I believe.

These might work. You would just have to patch the opening for the camera and put your clear window in. Not sure where you would find them though.

http://www.chinamarinewholesale.com/inflatable-tubes-boat-inflatable-tube_p297.html?zenid=do1c2cbjt994gck056g7a1fcn5

or one of these.

http://www.poolfloatsmart.com/foam-pool-floats/suncliner-hammock-pool-float-3142.html

Thinwal pvc sewer pipe would be a be a better choice and you could put a T front and rear and add an outrigger on both sides for better stability. They make pointed pvc piling caps available at a Marine Hardware store or website.

you could also add a clean-out T in the middle of the main tube with a screw cap to have easy access to the camera.

It great you came up with this independently. I had planned on the pyling cap already and the hatch. The problem still is where do you get a thin walled pvc pipe at 10 or even 8 inches? Every vendor I checked (over 20) says yeah they probably make it but I don't know where to get it. Thanks for the input. Pete

At 10", it looks like PIP is thinner and lighter than gravity sewer pipe.

Have you checked an irrigation supply place?

Unless I have misinterpreted your posting, buoyancy shouldn't be a problem with PVC since there will be a great volume of air within your camera enclosure. At 10" i.d. a foot of pipe with caps will provide approx. 35 lbs of buoyancy.

As suggested in another reply, use the lighter weight thinner walled sewer pipe. There are numerous fittings available for them and many of them can be modified to fit your needs.

Good Luck, Old Salt

Sorry for the confusion. The housing will be flooded with water so it can be lowered to predetirmined depths. It will be weighted only enough to be near bouyant. While underway the camera will look down into the water. While onsite i will change up the weight and floatant to give the cylinder an upright attitude. The camera will shoot horizontally.

How deep will this housing go? (~0.43 psi external pressure per foot of depth.)

EVER SINCE digital cameras made our inventory of Nikonos Underwater (35mm film) Cameras OBSOLETE , it has been a struggle to achieve and maintain a uniform inventory of identical-or-even-similar U/W photography packages.

The changes in digital camera technology keep pace with pc's (for all intents and purposes), and the manufacturers of U/W housings can't keep up with all the changes. Even as they TRY, we have found that their best efforts don't quite do the job. One "all-new" camera housing recently prompted us to invest in 4 new (expensive) digital cameras ... only to learn, in short order, that the housings (about $1500 apiece) develop "spider cracks" in the acrylic within just a few months outside the warranty period.

QUESTION: Why on earth would you prefer to be towing the camera, instead of having it installed IN the kayak with you (either "glass-bottom", OR in a hydroscope)?

Towing it will introduce all sorts of obstacles with respect to operation thereof, not to mention repetitive retrievals to observe your results ... and subsequent re-deployment.

If you have it IN the kayak with you, instant adjustments and re-takes will insure results which might otherwise "get-away" from you.

Granted, a full-blown ROV (remotely-operated-vehicle) with camera mounted on it could provide photo-ops that otherwise couldn't be achieved [just as a scuba-diver, "drifting" with a mild current over a reef can document unfathomable beauty].

......'course , if all you're looking for is "outlines" of "big-stuff-lying-on-bottom" ... you just might be successful.

Otherwise, seems like you're trying to re-invent a wheel that has long-since been eclipsed.

U/W camera stuff (for ideas) HERE, HERE, HERE, and HERE. <certainly, not all-inclusive>

Wishing you "the best" and success ~

"Edit" ~ having just seen your "Post#10", it still seems you are referring-to use of a camera for "still-photography" as opposed to video. Can't help but wonder what your intended subject material is, and what kind of results you hopefully expect...(?) Have you perchance tried any "snorkle-shooting" u/w, with a cheap disposable underwater camera...?

While I am certain you have the best motives with this post, it does miss the point of what I am trying to accomplish. I am not prepared to go into detail here about what I want to do as it would be off topic and pointless. I have underwater solutions such as the GoPro Hero cameras and their superb underwater housings at a great price. I simply need to find the cylinder and not have my methods questioned. That sounds harsh but I dont mean it that way. I know you were trying to help. I sincerely thank you for trying to help.

use square section plastic extrusion at least 3 or 4 mm thick, we tried round tubing in the Red Sea/Gulf years ago, tried weights to keep it in one position that is vertical but found square was the way to go, not with a point (where all four side meet in front), but the top and bottom meet one foot in front (sides are parallel)... plus small stabiliser top and bottom (two on the bottom one behind the other, to keep the straight line) and if you are towing it maybe side fins too.

We tried screws etc for sealing it, but found machined plexiglass with a double "O ring" did the job as the water pressure would maintain the seal and we just used retainer clips/catches to hold the door in place until water pressure took over

Please remember to place your camera window OUTSIDE the pipe with suitable "O rings" as again water pressure will maintain the seal (as it won't push through/inwards), and silicon glue.. NOT the domestic bathroom sealer type.

You also must experiment with the units' buoyancy, if you use fins, then weight them little by little as salt water has a great density than fresh water and what looks good in the bath, is not so good in the sea.

AND if you build it.. whichever way you want to.... and it does the job.. lets see the photos.. Cheers!