One Person Submersible From a Plastic Drum




(In the near future I will be attempting to upgrade to steel ballast)


Also, to all who comment saying that I will be sued for reckless endangerment, its not illegal to share a dangerous idea on the internet.

Many years ago, as an imaginative child, I dreamed of building my own submarine. Its been many years, and now I have the skill, and knowledge to make one myself.

Now its your turn...

This cost surprisingly little, and consists of only a few parts. Because you could probably make your own from one picture, this Intractable is more to inspire and document than to instruct.

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Step 1: Materials

- a Plastic drum 50-55 gallon (about person sized)
- one or more 5 gallon buckets
- medium strength rope
- about 12 ft of 2X4
- enough cement to fill several 5 gallon buckets
- a reciprocating or rotary disc saw (dermal/rotozip)
- Plexiglas
- silicon caulking
- short stainless steel screws
- boiler valve and some fittings
- eyebolts with nuts, and washers

Step 2: Window

Using the saw, cut a hole in the side of the barrel one inch smaller than your acrylic.
Drill out the holes where the screws will go in both the barrel and the window, this will prevent splitting
Before screwing the window to the hole, apply silicon glue liberally.
Screw down the window, such that all of the silicon spreads, and forms a continuous seal around the seam.

Step 3: Ballast

1) learn how to mix cement, if you cant find someone who can

there is no real way of telling how much cement will be needed to sink all of the air, but if you assume that the air takes up 2/3 of the drum, and ones head and shoulders take up 1/2 of that, than it can be assumed that there could be as many as 20 gallons of air, the buoyancy of which must be overcome.

So, math time:

Density of water = the total density of the submersible necessary for neutral buoyancy = 1

Density = mass/volume
density of cement = 2.4
(density of cement x volume of cement)/(volume of cement+volume of air)=1
(2.4 x C)/(C+A)=1 (C= volume of cement, A= volume of Air)
2.4 x C = C+A
Thus, 1.4 is the ratio of cement to air, and for 20 gallon of air, 15 gallons of cement should be needed. That means about three 5 gallon buckets full.

Step 4: Mixing Cement

 Mixed cement should be poured into buckets as molds. A bolt should be set in the cement with a washer to hold it in, and suspended in the middle as the cement dries. When dry, the bucket can be removed by hanging the block from the bolt, and tapping the bucket with the handle of a hammer.
Do this three times in a row, or all at once, if you have enough buckets and cement or whatnot.

Step 5: Mounting Ballast

 4 foot long sections of 2x4 work well as frame to suspend the weights from.
The way in which one attaches the ropes that suspend the frame is dependent on their barrel, but i used a repeating up/down pattern so that only one piece of rope would have to be used.

Step 6: Valves

 I don't have any pictures, but ill see if i can put some up later.

It would be a good idea to install a valve at the top to adjust air levels inside, and acheive neutral buoyancy

this could also be helpfull in replenishing the air supply between dives

Step 7: Safety and Accessories


if you DIE, I am not responsible, YOU took this on at your own risk
drowning is very possible in the device, I suggest using it in a pool first, using it with an adult, and doing primary tests unmanned.

SUFFOCATION IS ALSO A HUGE SAFTY RISK, limit dives to no more than five minutes, and be sure to get fresh air into the chamber between dives.

EMBOLISM: the popping of your lungs. always exhale while ascending.

for accessories, I would say: cellphone/ walky-talky in a jar, emergency air supply (compressed air in a bottle), timer fo watching dive times. goggle or mask, knife for cutting ropes and freeing weight if situation becomes dire.

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    159 Discussions


    4 years ago

    attach air tanks or bottles to make safe and jettsionable ballast


    4 years ago on Introduction

    Hey all! It's been fun watching the back&forth between people citing credentials and threaten to sue me and people who don't take the internet too seriously. I'm surprised to see the hoopla has persisted so long but I'm glad my simple suggestion has been so entertaining. Heres to many more years of reasoned discourse!

    Hi. I am a certified OSHA and CSAO commercial diver air dive supervisor, level 1, and qualified Master Scuba Diver Trainer with the Professional Association of Diving Instructors.
    This is a very dangerous idea. You might not die, but someone else might/will/and has.
    Just because there is a disclaimer there, you and Instructables will be subject to litigation. There is a reason that people need a certification to operate this type of life support equipment.

    "Because of Boyle's law, maximal changes in volume occur in the 4 feet (1.22 m.) closest to the surface and the diver sustains a tear in the pulmonary parenchyma with the escape of air into the pulmonary venous outflow."

    I can quote other resources, such as the US Navy Dive Manual and the DCIM manual, but it's Boyle's Law, not Boyle's "kinda' might happen. I don't know".

    16 replies

    What are you saying ? The reference you quote seems to be commenting on holding one's breath when coming up ?

    I don't disagree with your comments about it being a bad idea, but there is no way that publication is an endorsement of the safety of the concept.


    The way this works is:
    you submerge the bell (cause that is what it is)
    the air is trapped and you dive down and enter the bell.
    If you take a breath of air in at 4 feet or greater and hold your breath. Very bad things will happen and you will be dead in five minutes.

    If a four year old can be tried for reckless endangerment, for riding his bike on the sidewalk, then I can't see why the creator of an instructable of such an extremely dangerous piece of equipment couldn't be held liable. perhaps not in criminal court, but in civil court, for sure.

    The trapped air is at the 4 feet of water pressure, presumably then, or 1/8 Bar.

    Very bad things happen if you don't breath out ?

    Don't you get a strong urge to breath out as you come up anyway ?

    oddly enough, we are programmed to hold our breath underwater. everyone does it. even little babies will hold their breath underwater.

    Seriously? The guy who likes to hold babies underwater is talking about safety? How about not holding babies underwater, that would reduce liability a lot.

    slander: the action or crime of making a false spoken statement damaging to a person's reputation.

    Spoken,,, The term you're looking for is "libel"


    Reply 4 years ago

    You do realize that 15 of your 28 total comments were used to harass this guy about an idea he had (which, by the way, was an awesome first idea for a modified diy diving bell) right? Who did you troll with the other 13? I'd get a kick out of reading those too...

    couple things.

    1. You don't need to be a lawyer to know the law.

    2. I wasn't trolling. I honestly believe it to be dangerous.

    What you did with your comments, that's trolling. Bye now.

    Wait... Aren't you the guy who advocated holding babies underwater or something? I hate to go through the whole thread to figure it out.

    I myself would neither:

    1) Attempt to participate in diving bell design, professionally or amateur, without having the appropriate legal paperwork done first to assign rights, quality control, and liability.

    2) submerge infants, or in any way use children in testing. I understand that in some parts of the world children are utilized as labor, and are used in high risk environments. I mean no offense to your methods or culture and any use you make of children, but I do not personally support the practice.


    I hope the last year has treated you well. I had forgotten about this thread with all it's sillyness and seriousness.


    Reply 4 years ago on Introduction

    I liked the guy's diving bell instructable. I think he caught way more flak than he should have.

    I do agree that I made a joke earlier in the thread about submerging kids, you did not seem to get it was in jest, and in response clarified that you would not do such a thing, and I take you at your word. My later comment about not submerging babies was an effort to clarify that I myself do not condone or utlize the practice either.