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Why Build a Sub

Jacques Cousteau  (1910 - 1979)

20,000 Leagues Under The Sea

Like so many other's it all started with watching the "The Undersea World of Jacques Cousteau" and pretending to be sick so I could skip church on Sunday night in order to watch "20,000 Leagues Under The Sea" on the "Wonderful World of Disney".  At age 43 my sins gave way to scuba diving, which led to building and ROV, which went so well that I decided why not a submarine?

Before building a submarine in your backyard or any other such nonsense, inventory your skills, resources and commitment.  Then start setting goals and enjoy the journey. Remember that a dream is a choice you have not made.


First gauge your commitment and then that of your family.  Skills and resources can be developed, and tools and materials can be replaced but families are fragile and vital.  Make sure they understand the time, energy and focus that will be required, especially if your lacking in the skills and resources categories like I am.


Goals are a must, but they are tricky things.  I keep mine in three categories: "short term", "long term" and "that would be cool".  For me, all three are equally important as they separate dreams that will only be dreams from dreams that are obtainable.  The following is my "that would be cool" that goal. 

My wife Kay and I are cruising at 35 feet beneath the near shore waters off the Florida east coast. The gradiometer on the bow has detected a slight distortion in the earths magnetic field and is guiding us toward a coral head.  There at the base of the outcrop I can make out what might be a cannon.  I bring the boat to a stop, extend the landing gear, and press the down button on the automatic ballast control system.  Air escapes from the soft ballast tanks and the boat comes to a gentle rest on the sandy ocean floor.   Another button engages the ballast sled lead screw drive and the ballast moves slowly forward.  We open the clear acrylic hatches beneath our feet, and the water rises less than an inch into the sub until it finds its' new equilibrium with the sub's ambient air pressure.  The ballast sled is now in it full forward position and I put on a dive mask and drop through the open hatch just long enough to retrieve two air lines stored on the front deck.  We connect our regulators to the air lines and check the pressure gauge for the high pressure air tanks stored in the pontoons on each side of the sub.  Then both of use slip through the bottom hatches and out from under the bow of the submarine.  We release addition air line stored behind the cabin so that we can now range up to 80 feet from the submarine.  Without scuba tanks we only wear 8 pounds in our weight belts along with dive shears and spare air bottles for emergencies.  We head straight for the iron object that drew the attention of our gradiometer.  It is a cannon.  It is crusted over with centuries of sea life but the muzzle opening is unmistakable.  I look up toward the surface and imagine hull of the the ill fated vessel split open by the coral head just under the surface.  

Jacques CousteauThere is nothing quite so relaxing as hovering weightlessly in the sea, hearing nothing but the whisper of air when your regulator opens and the sound of your exhaust bubbles. Looking at indigenous sea creatures going about their lives as though you are not even there, at times you forget that you are only briefly visiting this strange and wonderful part of our planet which makes up two-thirds of the Earth's surface.
--Jacques Cousteau

But the Poster
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A dull clanking calls my attention back to the sub where Kay is opening the wet storage compartment on the mid deck. I swim over to assist her, when the hatch opens I put my hand down on the small ice box to prevent our lunch from floating away.  We will have to start eating heavier lunches or add a few more ounces of lead to the bottom of the box.  Kay reaches past and retrieves the metal detector and heads back to the sandy plane south of the coral head.  If a hurricane ran this ship aground then the trail likely leads south west from the impact.  I secure the hatch and follow behind.  The the detector beeps and I fan the sand away from the spot to revile a blade from a boat's prop.  Definitely not of Spanish origin but likely the result of a much later encounter with the same coral head.  Several rusty bolts and one oil filter latter we are ready turn to start another transverse, still searching for a debris path.  The detector sounds again and I swish the sand aside.  Another piece of iron mostly eaten away but it has a square head.  It's a nail, but not any nail you would find at Home Depot, this nail is old.  I mark the location's bearing and estimated distance to the coral head and the rejoin Kay.  Suddenly the sand billows in front of us, we both recoil from the startling movement.  A large flounder sprang from it's resting place we share a little laughter over our mutual reaction.  The sand settles back into place and the gentle current clears the water ahead, the sun filtering thought the water glints off the bottom like dozens of small search lights, but from one spot the glint is bright.  Our eyes come to the spot were the flounder was resting, and there laying in the sand is a small golden cross.  It lays peacefully on the bottom now, but I think about the plight of it's previous owner.  After logging the location we return to the sub.

Back in the dry cabin, we enjoy a lunch of cheese and crackers, watch the fish outside our windows and make our plans for surveying the site.   After 2 hours of bottom time we store the air line, close the bottom hatches, send the ballast sled aft about 3 feet to it's submerged running position, and set our depth to 0 feet.  When the sub lifts off the bottom I flip the switches to retract the landing gear and engage the two 36 volt thrusters.  We tour the coral head on the slow rise to the surface.  When the cabin breaks water, I turn on the bilge pump so that it clears the water from the engine snorkel, and 60 seconds later the diesel engine fires and the jet pump begins to quickly pump the water from inside the hull.  The water is drawn through the same intake diverter  that was used to flood the hull when we submerged.  As the hull empties the ballast sled lead screw is moving the sled further aft causing the bow to rise slightly.  With rear deck still awash we cruise over the coral head and watch the seen below thought the bottom hatches and the acrylic bow where we rest our feet.  In minutes the view through the bottom hatch is broken by air and spray.  With the the hull is almost empty I turn the boat toward home and increase speed.  As the remaining water is drawn from the hull the boat slowly rises onto its V hull, lifting the heavy load from the water and further increasing its' speed.  With a flip of a switch a pneumatic piston closes the diverter. The water remaining inside the hull will be removed with a small bilge pump.  While the engine is running, it is also recharging the 36 volt system which powers the thrusters as well as the 12 volt system which powers the on board electronics and starts the engine.  At 24 mph the waves and spray are a blur through the bottom hatches as we skim across the water.  Soon the sub will be back on her trailer and readied to continue the search.

Enjoy the Journey

Dream in the weeds.Something I wrote on my web site 6 years ago: Someone wrote me and asked " other sub owners you may know find the time to use their subs regularly or does it tend to be for a short time after they are first constructed?" My reply was "I think most home built subs that get built, are used a couple of years and then just sit in the garage, and then in the side yard, and finally as a road sign for a dive shop or worse." "Frankly I recognize that this may be the fate of my own boat, however even if it were a near certainty, I would still be building it anyway. For me the reward in is the journey not just the destination. I have already learned a number of new skills. Having paid for a number of college and technical training classes, the $12,000 cost of my sub in comparison, was been money well spent. Also important to me is that the sub gives me the opportunity to work together with my son, we have always spent time together but this is the first opportunity that I have had to let him have a role in designing parts, presenting ideas, and working with the tools. It's also a role modeling thing, in that my son gets to see what it takes to tackle a big project." My point is that there are lots of home build subs sitting in weeds that may have never made it to the waters edge, but they are not necessarily unfulfilled dreams. At worst they were a learning experience, but the important thing is they represent one more person who dared to follow a dream.

When I started I set my goals based on time. For example 2 to 3 years for the complete project and the main hull will be completed by such and such date. That was a mistake. I was placing constraints on how long it would take me to lean new skills and while leaning to weld aluminum was not bad at all, learning to cast aluminum parts was very time consuming and at first I didn't even list it as a requirement. I could have made do without this skill but it truly has been very helpful, fun, and it is saving me a lot of money. So I no longer set completion dates for various components, instead I set my short term goals for spending a minimum number of hours each week working on the sub. The number of hours can vary from week to week. I when I don't work on the sub for a couple of weeks it is a planned break. I know the day I will be back in the shop and the part I will be working on. This makes answering the question "When are you going to be finished?" hard to answer, but my time in the shop is also more enjoyable. And my long term goal is to have fun.

Follow Your Dreams

Here is a little story I remember from somewhere in my youth.

There once was a great flood that sweep across the prairie. Amongst the waters floated a hawk nest that been torn from a fallen oak. The nest and the sole egg that it carried, came to rest in a clump of grass where prairie chickens had laid a clutch of eggs. When the adult prairie chickens returned to their nest they looked at the hawk egg and then pushed it into their nest; thinking it to be one of their own.  The hawk egg was considerably larger than the other eggs but prairie chickens are not known for their powers of observation.

Soon all of the eggs hatched and the little hawk took her place beside the prairie chickens. Many days passed and the hawk learned quickly how to live life as a prairie chicken. Much of the day was spend scratching in the ground for grubs and worms or running after a grass hoppers or crickets. The rest of the day was spent hiding deep among the clumps of grass.

The prairie chickens faced many dangers from coyotes and the birds of prey. Their only defense was to keep a sharp eye out for the predators and rush to their hiding places before they were seen.

As the chicks grew the little hawk soon was twice the size of the other chicks and looked very different. The prairie chickens took little notice that the hawk was different even though it clearly looked like one of their predators they so greatly feared. Prairie Chickens are not known for their powers of deduction.

One day the hawk stopped scratching in the dirt and looked high into a clear blue autumn sky. Far above it could see a pair of hawks gliding on the currents of air. The hawk sat motionless on the ground so it would not be seen; but then the hawk did something it had never done before. It wondered what it would be like to soar so high above the earth. The hawk began to dream of a life where it was a powerful bird, gliding across the prairie and over the peaks of the mountains.

Then a grass hopper jumped onto a blade of grass in front of the hawk and the dream was gone. Prairie chickens are not known for ability to follow their dreams. The End.

Don't let the prairie chickens around you set your standards. Dare to dream and dare to follow your dreams.  --Doug J