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Hi Brandon.
There are others at this forum more knowledgable
than I that might help you with certain technical aspects that I cannot, but I
will endeavor to help and advise you as best I can.
First let me say that you must be dedicated to
building this sub completely. Otherwise it will wind up an unfinished project.
Even a susposedly simple wetsub can be quite complicated actually. I know. I own
one.
I will address your concerns and question in
order.
1. You do not need a dry suit to have audio
communications. You just need a full face mask with communications built into
the mask.
2. If you want to do barrel rolls you cannot use
cheap, easily available car or marine deep cycle batteries. If you roll
frequently you will spill your acid out into the interior of your battery
compartment using those types of batteries so you will
have to use more expensive non lead acid batteries
in your design if you want to barrel roll the sub. Also you want stability in
your wetsub so that means you need most of your buoyancy high and your weight
low. Most people put their
batteries and ballast low in order to keep
stability and to keep from rolling over inadvertently. Rolling might sound like
fun but why? In order to design your sub to roll it will cause you more design
work and problems with the batteries and ballast
weight. Most battery powered wetsubs are keel heavy
for stability so they will not roll over. You can build a rolling wetsub, but it
is more complicated.
3. Trolling motors are made in other voltages
besides 12 volts. My 74lbs thrust minnkota is 24 volts.
Trolling motors companies like minnkota will only
guarantee their products to 33ft. They are not made to go to deeper pressures.
Now you get into either oil filling your trolling motors or air equalization, or
have special ceramic prop shaft seals made to keep water
pressure out of the
motor. You will have to decide which system you want to use.
Or you could strap a couple of sea scooters onto your sub that are already
rated for at least 100 ft and believe me you might want to seriously think about
that since you would not
have to go thru the whole ceramic seal/air
equalization/oil filled trolling motor thing. Also there is the hydrogen explosion problem from the batteries and
isolating the motor from the battery gases going thru the wire strands and the
tubing from the battery
compartment to the motor. By the time you get thru
messing around making a trolling motor work to 100 depth and adapting that
motor and building a battery compartment and either oil or air equalize it, then
making sure you vent the battery compartment
properly to let hydrogen out when you
charge....AHHHHHH! Trust me, think about scooters strapped to a wingtank. Then
you could barrel roll all you wanted without a heavy battery pod under the sub.
If you don't have that heavy battery pod keel then you might have
a tendency to roll inadvertently. You could install
ailerons on the dive planes to correct that roll when you are at speed, but you
might not be able to control your rolling when you were stationary since you
would not have a heavy keel for stability.
Since you cannot dive to 100ft for 2 and 4 hours
because of dive table preclusions, I assume you simply want that much battery
time for multiple dives. Most times I will only dive two times on a given dive.
Sometimes 3. You really do not need that much
battery time and will only add unnecessary weight
by needing more and larger batteries for that length of time. Two good quality
(read that EXPENSIVE) powerful sea scooters with around 90 minutes of constant
run time is all you really need.
Two weeks ago I dove to 55ft spearing grouper on a
reef. I used my sea scooter on two of my three dives that day. It has
a run time of 90 minutes on full speed. If necessary I can surface and quickly
and easily change out batteries and get another 90 minutes.
You can't do a rapid battery change using a battery
pod on your sub's keel. Trust me on this one and consider using dpv scooters as
propulsion for your wetsub.
4. Why do you want wings? They are not necessary.
They do not hold you up like they do an aircraft. Dive planes will suffice.
Possibly ailerons on your dive planes if you want to barrel roll. Let me ask
you.....will you ever get out of the wetsub while underwater?
What if you see something you want to retreive? You
can't do that if you are slightly positive buoyant. The sub would float to the
surface. Also I am not nuts about a slightly positive buoyant wetsub. When you
do your 3 minute hang at 15 feet for no decompression
diving, how are you going to do that once you stop
the subs forward movement and the dive planes no longer hold you down? You will
not like having a wetsub you can never park on the bottom. What you need are a
couple of bladders or small ballast tanks that
you can vary your buoyancy with. Put one in the bow
and one in the stern. Have seperate lines going to them from your air tank so
you can trim the boat. If you do not barrel roll, then you can drill a hole in
the bottom of the ballast tanks to make sure you never
overill and burst them. Also think about this....if
you are in a bow up attitude, your air will go the the uppermost
portion of your bow ballast tank right? Suspose you want to drop the bow to make
the sub level called trimming the boat. You would want to make sure
your air release valve or hose on the ballast tank
was built into that end of the ballast tank, otherwise the air would be trapped
above the valve or hose and not exit the tank.
5. Although once certified as a diver in the U.S.
you are always certified. Your diving certificate does not expire here. However
if you have not done it in a long time I would recommend a refresher course
definately. It is suicidal and foolish for anyone to operate a
wetsub
without being a diver first.
6. How much will it cost? That depends on your
design. I would recommend a military surplus kevlar wingtank from a helicopter
that is 15 ft long, about 1/2 inch thick and very strong. Cut out your cockpits,
install your pivoting dive planes, rudder and sea scooters.
You could avoid dive planes altogether and just use
pivoting sea scooters in place of dive planes. Make the scooter removable so you
can detach them and use them for normal diving without the sub.
Then install your buoyancy bladders or ballast
tanks. It will be as expensive or as cheap as you make it. But I guarantee if
you make it correctly you will have more than a few thousand dollars in it.
Figure what you THINK it will cost. Then multiply
that number by 3. That will put you about right.
Hope this helped.
Kindest Regards,
Bill Akins.
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