[PSUBS-MAILIST] Dive report: Snoopy at Seneca

Sat Jun 6 02:03:56 EDT 2015

Sounds interesting, Al.  Towing the sub, following its track, and keeping
other boats away seem like good features for a chase/support boat.  Heavy
lift capability could also be handy.
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 8:29 PM
To: Personal Submersibles General Discussion
Subject: Re: [PSUBS-MAILIST] Dive report: Snoopy at Seneca

Tim,

It's basically a 20' 150 hp outboard...good for towing the sub out to the
dive site.  I have 2 other larger boats but they aren't as easily towed on
the highway.
I provided support for Persistence, Dan H's K-350 sub when we did the deep
test for that. 

Al Secor

--------------------------------------------
On Fri, 6/5/15, T Novak 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, 11:11 PM

 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
  --------
  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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