[PSUBS-MAILIST] Dive report: Snoopy at Seneca

Fri Jun 5 23:28:50 EDT 2015

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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