[PSUBS-MAILIST] Dive report - Pickles Reef

[Alec Smyth]

In Islamorada for the 2013 PSUBS convention, we tried a few days ago to
dive the reefs off the Atlantic side of the island. After towing Snoopy out
to the dive site, I had to call off the dive because a three foot chop made
it unsafe to board. I made it aboard myself, but water was splashing over
the hatch land, and with the weight of a second person it would have been
touch and go. When their hatches are open, these little boats are like
holes in the water just waiting to be filled up by the next wave. Three
foot waves are not large, and they are entirely normal a few miles from
shore, but they are just beyond practical conditions for Snoopy.

For our second attempt on the reefs we changed tactics, deciding to board
at the boat ramp and make the tow under a closed hatch. This would
guarantee a dive regardless of wave conditions, but also introduce a new
challenge. With a temperature of 89 degrees above the surface and 86
degrees below it, the problem was now how to avoid getting cooked during
the tow. There was hardly a cloud in the sky, and Snoopy’s big acrylic dome
hatch transforms her cabin into a greenhouse. The pilot, with his head in
the middle of the dome, feels that he is under a giant magnifying glass.
Hot air rises.

Steve McQueen and I boarded at Harry Harris state park at 12:30, after
having spent the morning at the local school giving four hundred local
children a tour of the sub. Snoopy’s payload can be maximized by adding
buoyancy spheres. We installed every available one, and used their buoyancy
to load twenty pounds of ice inside the cabin. Our support diver, Scott
Waters, attached a white hotel towel over the dome with bungee cord, and
then tied off the tow line. We set out, towed by Doug Suhr in his whaler,
an ideal surface support vessel. He had fashioned a custom wooden frame
that allowed towing from a point just aft of midships. That is where tugs
and trawlers attach their tow lines, and it allowed the whaler to retain
good control, whereas in the past I had found Snoopy often turned around
the towboat when towed from the transom.

The tow was unexpectedly interesting, because of the bottom rushing by and
constantly changing scenery. Most of the time it would be sand and sea
grass, but there were always changes and it would at times become more
rocky, or turn to pure sand, and drop away or rise up to just a couple of
feet from us. We rushed past or right through clouds of jellies. As Steve
put it, it felt like an arcade game.

I have no idea how hot it was inside the sub, but it was surely an
outrageous number. Prior to departure we had applied detergent to the
viewports to prevent them from fogging. That succeeded on the forward
viewport, but with that single exception every other surface in the boat
streamed water profusely. Every ten minutes or so I would pick up a rapidly
dwindling bag of ice and give it a hug, rest it on the back of my neck, or
wear it as a hat. I went through five bottles of drinking water.

Between the rolling of the boat, and the heat and humidity, I found myself
getting a bit woozy. It was not sea sickness so much as a feeling of
light-headedness, so we tried increasing the oxygen concentration in the
cabin to counteract it. Between us we had been consuming ¾ liters of oxygen
per minute, with the analyzer readings hovering around 19 percent and a
fraction. We bumped up the flow to 4 liters per minute until the oxygen
concentration reached 23 percent, a limit above which the cabin atmosphere
would have become a fire hazard. That is only two percent above normal, but
it made us both feel perceptibly better.

We arrived at the dive site two hours after closing the hatch, and rather
incredibly only four minutes after our target time of low tide. The twenty
pounds of ice had all melted. Our normal tow speed is three knots, and the
distance was only four miles, but some “hatch closed” time was spent
getting underway, some was spent on a stop to re-position the towel when it
was displaced by waves washing over the dome, and some was spent on the
final locating of the site.

Doug anchored the whaler and Scott swam over to remove our towel sunshade,
and to attach a video camera to the sub. In the previous few days the heat
and humidity had already led to the failure of a depth sounder and a
compass, so I had decided not to risk the good camera inside the sub. In
tropical climates at least, the cabin is a very dangerous place for
electronics.

We initiated our dive and tested communications as soon as the transducer
went under water. The gear worked, yet the communications were very faint.
Snoopy’s transducers are mounted above the hull and immediately behind the
conning tower. Being just beneath the surface and pointed in the direction
of the whaler, the transducer’s line of sight to the boat was blocked by
the conning tower. Once at depth the communications were loud and clear.

The reef was unfortunately not healthy, as all reefs in this part of the
world, yet it was absolutely fantastic compared to the lakes Snoopy
normally dives in. There were large sponges, fish, and interesting terrain.
In particular, we found “streets” of sand running between raised mounds of
coral on either side, reminiscent of scenes in the movie 20,000 Leagues
Under the Sea. Visibility was about fifty feet.

In Snoopy, almost all the viewing underwater is done through the bow
viewport. Through the dome it is very hard to see the bottom unless diving
alongside a wall or quite high terrain, and even in that scenario optical
distortion causes features to appear very small and far off. Nonetheless,
while I could hardly see the bottom through the dome, I did see a column of
bubbles rising in the distance and steered Snoopy in their direction. It
was Scott, who had found a lost anchor. He tied it to Snoopy’s pickup arm,
and we blew some air into the ballast tanks and delivered it to the boat.

We continued wandering the bottom, sometimes letting the current waft us
along sideways and other times using the stern thruster to follow the “sand
roads”. These gradually led into deeper water, and we followed them hoping
for the continental shelf drop-off that is only a short distance from
Pickles reef. We started at thirty feet, and followed these paths down to a
little over fifty feet, but unfortunately did not make it as far as the
drop-off.

Snoopy was ballasted ever so slightly buoyant, perhaps just a pound or two.
One side thruster was locked in a straight down position, the other
slightly inclined to counter the rotation induced by the props. Indeed the
props only needed to turn very slowly to maintain depth, as if turned by
hand instead of by a motor. To slowly rise I would shut them off, or I
would speed them up to descend. The side thruster throttle acted as a
“depth knob”, allowing depth to be controlled with an accuracy of a couple
of inches.

Laying prone and looking out of the forward viewport, Steve had a good view
of upcoming terrain. He acted as observer, calling out details about what
lay ahead and asking for port or starboard headings and altitude
adjustments. One tries to stay close to the bottom in order to see it
better, but not touch anything in order to avoid damaging the reef. He took
a turn at the controls as well, which in Snoopy does not mean that we
changed places, but rather that we passed the remote controller between us.

At one point we lost communications with the surface. We were to learn
later that the whaler had re-positioned to follow us, and in doing so ran
over its transducer cable, severing it and losing the transducer. The
whaler could have tracked us by our acoustic pinger, but instead simply
followed the bubbles of our support divers, who were following us by sight
in the clear water.

After an hour and a half of contented wandering, we suddenly sensed that
the stern thruster had lost power. A moment later we both noticed a smell
of burning. I turned off power to the stern thruster speed control, looked
up to ensure we were not under the whaler, and immediately initiated a
ballast blow, which gives a much faster rate of ascent than the thrusters.
We could have continued maneuvering on side thrusters only, but it seemed
prudent to call the dive. Afterwards I would discover that a little piece
of fan coral had been sucked in by the stern thruster, and wedged between
the propeller and its shroud. It was very tough material, and it locked up
the thruster causing its speed controller to burn out. Although the speed
controllers are supposed to have over-current protection, I will be adding
breakers in the near future.

One more surprise awaited us during the tow back to shore. After about an
hour of towing, we had reached a spot at which the waves were lower, and we
were on the radio to the whaler planning to pause the tow and transfer to
her. But just then there was suddenly a very loud pop in the cabin, and my
immediate thought was of a ruptured high pressure line. It was followed a
second later by another equally loud pop. I was puzzled by the fact my ears
were not registering any increase in cabin pressure, when I saw Steve’s
life preserver inflating. These life preservers are of the type that
resembles suspenders, inflated by a CO2 cartridge which Steve’s movement
had accidentally triggered. For a moment it looked like his PFD might
strangle him in the tight space, but he managed to wriggle out of it. I’ll
be looking at some way to secure the rip cord on these PFDs, to make
accidental deployment a little less likely. There is precious little space
in Snoopy under normal conditions, but with an inflated PFD the lack of
space becomes almost comical.

Finally we came aboard the whaler. Being in the tower, I stowed my seat,
climbed out, and closed the hatch quickly behind me. This allowed Steve to
reposition himself into the tower without fear of being swamped while doing
so. The hatch opened again, Steve jumped out, and we were both on deck. It
had been five hours since we closed the hatch.

It was only once back on the whaler I saw Steve was quite hungry. It was
six in the evening, and he had avoided eating anything all day,
anticipating that it would be a long dive and knowing that Snoopy has no
head. Now that is dedication!



Cheers,


Alec
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