----- Original Message -----
Sent: Wednesday, November 03, 2004 9:15
PM
Subject: [PSUBS-MAILIST] Last Launch and
Trials
Hi All,
I apologize for not posting sooner. I was hoping
to have more to post.
I took my sub, Persistence, to the lake where I
first launched it for a day of diving. Although not a great dive
location, it's close to home and has a nice launch ramp. There are also
two docks on it, about 800 feet apart, where I planned to do timed runs to
determine it's speed.
Since the lake is located within a
state park, it's patrolled by park rangers. The part time "rent a
ranger" that was there on Sunday had some issues with my safety. Like HE was
going to save me from my own demise by not letting me in the water that
day. He insisted that I would need a "surface boat and a scuba diver in
the water to be safe to go in that thing." After discussing the
situation for twenty minuets, I could see that his mind was made
up.
I did launch that day in another lake about an
hour away but the location didn't lend itself to testing the subs speed and we
already spent a lot of daylight.
I got to test my fish finder / sonar more and
found it pretty difficult to tell much with. Maybe with more practice
I'll learn how to find more information in the squiggly lines. It's
great for determining depth and watching as I'm approaching the bottom.
It counts down until I touch down. I turned the pickup facing upward but
it won't read the distance to the surface when sitting on the bottom. I
guess it can't detect the boundary between the water and the air.
Another thing I tried out was a mirror I located
on the top of my hatch cover on the outside of the up looking viewport.
When the sub is on the surface, but still at neutral buoyancy, none of it
actually sticks above the surface. I can only glimpse out of the up looking
viewport. Seeing the sky isn't much of a help when trying to get a fix
on a direction or proximity to an object. It takes time and air to
inflate the MBT's enough to get the conning tower viewports out of the
water. With a small mirror, fixed at 45 degrees, located
above half of the hatch viewport, I can look up and see forward just enough to
scan the surface. I know it's no periscope, but it's simple and doesn't
have the hazards of a periscope in a small sub.
I recently posted a request for help in choosing
a method of keep on course under water. I thank each of you who posted
suggestions. After reading your postings and considering my options,
I've decided to try to find a liquid filled dash board compass
to mount outside the pressure hull as a first try. They're hard to
find now with electronic ones on the market.
My second choice would be an electronic compass
made in two parts. If I can find such a unit, I'd encapsulate the sensor
in epoxy and mount it under my fiberglass MBT, pass the wires through a
thruhull and mount the readout inside. I've found some one piece
electronic units and some sensors but I don't have the electronic skills to
separate the one piece units or marry together a sensor and
readout. I don't want a whole computer in the sub.
If anyone knows of an off the shelf unit or could
give me explicit instructions, I'd like to try an electronic compass with
remote located sensor.
My last choice, probably the most expensive, is
to install a 28 volt aviation gyro compass. The biggest draw
backs are it needs to be set each time, it's noisy and an
electronic gyro is expensive. They are a nice, easy to install
and use, one piece unit that will work well in a sub.
That's it from Persistence! If I get a
chance to test speed or a guidance system before the lakes freeze over, I'll
post my progress.
Cheers to all, Dan
H