[PSUBS-MAILIST] Dive report: Snoopy at Seneca

Fri Jun 5 23:11:57 EDT 2015

What kind of surface support boat do you have, Al?  Could you post a photo?
Tim

-----Original Message-----
From: Personal_Submersibles [mailto:personal_submersibles-bounces at psubs.org]
On Behalf Of Al Secor via Personal_Submersibles
Sent: June-05-15 7:19 PM
To: Personal Submersibles General Discussion
Subject: Re: [PSUBS-MAILIST] Dive report: Snoopy at Seneca

FWIW, my boat is available for any surface support for deep tests and I can
also provide guidance to local wrecks in Seneca if anyone else is
interested.
I also have a scuba compressor for air fills.

Al Secor

--------------------------------------------
On Fri, 6/5/15, swaters at waters-ks.com via Personal_Submersibles
<personal_submersibles at psubs.org> wrote:

 Subject: Re: [PSUBS-MAILIST] Dive report: Snoopy at Seneca
 To: "Personal Submersibles General Discussion"
<personal_submersibles at psubs.org>
 Date: Friday, June 5, 2015, 9:20 PM

 Alec,So
 cool. I wish I could of made it! Can't wait to see the  video.Thanks,Scott
Waters

 Sent from my U.S.
 Cellular® Smartphone

 -------- Original message
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 From: Alec Smyth via
 Personal_Submersibles
 <personal_submersibles at psubs.org>
 Date:06/05/2015  5:16 PM  (GMT-06:00)
 To: Personal Submersibles General Discussion
<personal_submersibles at psubs.org>
 Cc:

 Subject: [PSUBS-MAILIST] Dive report:
 Snoopy at Seneca 

 Hello
 friends,
 I just got back
 from a dive trip to Seneca with Dan Lance and thought  I'd share how it
went. This was supposed to be a two sub  trip with Scott Waters, but
unfortunately a business  emergency intervened and it ended up being just
Snoopy.
 On the way up
 the weather was terrible, with driving rain so heavy I could  barely see
the lines on the road. It had been raining  heavily for several days
previously. Three times there were  emergency announcements about floods,
large hail, and  damaging winds, and the closer I got the harder it rained.
 The problem with all that rain is that in your typical lake,  the runoff
ruins visibility for weeks. That is what happened  last year when
Trustworthy and Snoopy rendezvoused at  Summersville Lake, and it looked
very much like this would  be a repeat. I'm happy to say Seneca must be
rain-proof,  because the deluge only reduced the visibility in the top
fifty feet or so, and even those were clearer than most  lakes.
 Here's a
 few things we learned:
 1) Of props and
 shroudsThe stern thruster speed control was dead  on arrival, although I
had tested it successfully before  leaving. I opened up the enclosure,
pressed down all the  spade connectors, and found it now worked - so
attributed  the issue to road bumps. However, it died within a minute on
the first dive. I had a spare speed controller, so switched  it out.  The
replacement died within five minutes on the second dive.
 This time at least the cause was obvious, the prop was  jammed by weeds.
The current Minnkota props have a little  twist at the end of the blades,
and Snoopy's shroud is  made with almost no clearance. The little twist to
the blade  tip causes any object coming between prop and shroud to jam
tight, and had already smoked one controller during the  convention in the
Keys. I'm going to put the prop on the  lathe and take off the tips to
eliminate the pinching effect  and to reduce the amperage draw a little so
the motor goes  lighter on the speed controller. By the way, the speed
controller was protected by a fuse rated a little below the  controller spec
current draw, so perhaps those specs are  optimistic. Anyway, as a result of
the double failure all of  our dives were done on just the side thrusters
because I was  out of spare speed controllers. Lesson for next sub: Design
the electrical system with a controller bypass, so I can  operate thrusters
with simple on/off switches if a speed  controller fails. They're
electronic, they will  fail.
 2) Of air
 bubbles in compensation oil
 Snoopy is now routinely diving deep
 (250 ft) and this has showed up a puzzling issue with the  thrusters. They
were feeble during dives, one died  altogether on one dive, and they kept
coming up leaking oil.
 At first we thought the seals were failing, perhaps due to  some chemical
incompatibility. We found suitable seals at an  Amish farm supply store that
sold things like tractor spares  (viva trolling motor simplicity!) When I
disconnected the  bladder hose I got quite well sprayed with oil. The motor
turned out to be pressurized.  Previously, I thought if one had a  small
quantity of air left in the system it would not be an  issue so long as the
compression volume of that air could be  handled by the flexibility of the
hose (aka compensation
 bladder.) Wrong. I now think what happens is that if the  dive exceeds the
pressure rating of the shaft seal and there  is a bubble of any size, you
will get water added to the oil  and the bubble stores the pressure. Upon
surfacing,  the bubble squeezes oil and water back out until the  pressure
in the motor falls to the "cracking  pressure" of the seal. Thus, you get an
oil leak even  though the seals are fine. Lesson: Zero tolerance with oil
bubbles, even a small bubble is unacceptable if you are  diving deep. I'm
going to put set screws on the motor  caps so I can get rid of the bubbles
more  easily.
 3) An easy way
 to add buoyancySnoopy's buoyancy is adjusted  by placing trawl floats in
PVC tubes. On one occasion, the  oncoming passenger's weight required the
addition of  just one float (i.e. the new guy weighed seven pounds more
than the one getting off). The support diver wasn't  suited up and the water
was 42 degrees, so I just pushed a  float under the lip of the forward MBT.
It worked like a  charm, and the float even stayed in place throughout the
tow  back to the ramp. Lesson: You can easily add a few floats  for buoyancy
on a standard K sub, no special tubes  required.
 Most of our
 dives were along a very steep incline, not quite a wall but  more like a
series of ledges and very steep slopes. Between  the steep terrain and the
good visibility, the K250 dome for  once offered a really good view. We
typically made our way  down the slopes using very slightly negative
buoyancy,  trailing the back corner of a skid on the slope. Looking  aft,
you could see a zigzagging trail of silt hanging  motionless in the water
and tracing our path. The sub  compresses with depth, so slightly positive
buoyancy at the  surface turned into slightly negative at depth, but  we're
speaking of just a couple of pounds and not  anything that caused
difficulty. In fact at one point we  stopped dead in the water four or five
feet above a flat  bottom for about five minutes, just waiting for a
pre-arranged touch-point call on comms. The sub didn't  rise or sink an
inch, she just hung there completely  immobile for five minutes. At about
140 feet the visibility  would improve significantly, and the water changed
from  green to blue. It looked like ocean instead of lake water.
 I'll post a video, but that'll take a few days to  put together. The only
"incidents" we had were a  cold bath we took when we closed the hatch over a
corner of  the crew's shirt, and when we got hooked on a log at 220  feet -
fortunately reversing got us right off  it.

 Best,
 Alec 

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