|The Sink Cam. Light reflector made from
a 12" stainless steel bar sink and a Halcyon 18 watt HID cannister
light. That's an OMS depth gauge mounted just above the camera's 2"
LCD monitor window. The black pontoons are 2" diameter PVC intended
to add buoyancy. The ones shown proved not to add enough buoyancy.
Since the light mount was already built for a 2" diameter, I
couldn't go with larger diameter pipe, so I had to add length.
||The Sink Cam battery cannister mounts to the underside
of the custom-made aluminum framework. Having the weight low helps
keep the camera trimmed evenly in the water. The twin batteries for
the camera's 10 watt HID light arms are just above the black cannister.
Although it appears from this angle like there is a tangle of wires,
it's actually pretty tidy in the water. The line knotted on the right
side is a safety line to clip off on a D-ring in the water.
||Front view showing the plastic diffuser, made from
a thick vinyl office chair floor pad. The diffuser mounting ring is
cut from a single piece of thin aluminum stock. Although there are
factory-made lights that do the same thing (okay, probably better)
the Sink Cam works very well to cast a diffuse and even light pattern
over the camera's view field, while the 10 watt arms provide a "hot
spot" light that hits the subject, and also work together to
The Dive Sled. The
frame is bent from a single piece of round 1/2-inch aluminum stock.
The blade is 1/4-inch. I designed this sled to get around what I
see as the major deficiency of other designs; namely, diver fatigue
from having to hold on to the blasted thing while being towed through
the water column. The tow line attaches to the tongue of the sled
(left side of photo) with a quick-release stainless caribiner. The
yellow strap on the left is the quick-release "rip cord"
and trains over the top of the sled where it can easily be grasped
by the diver and pulled to release the SLED from the BOAT. The sled
is an absolute thrill ride at speeds up to maybe 4 knots. Easy to
control depth and trim, non-fatiguing to ride, and a great way to
cover some serious area when performing an underwater search.
In this design, the diver clips
the green strap caribiner on to his crotch strap D-ring and adjusts
the strap length so his body positions with the head and shoulders
over the fulcrum of the plane, and the arms slightly bent so he
can grap the handles comfortably. The round float and the short
yellow cord is attached to another quick-release stainless caribiner.
The float rides just under the diver's chin, and when pulled releases
the DIVER from the SLED. This is the emergency release, since the
sled is balanced in such a way that it dives straight for the bottom
without someone to steer. The only way to retrieve a driverless
sled is to stop the boat, let the sled sink to the end of its towline,
and retrieve it slowly.
The underside of the sled, showing
the attachment detail of the wing to the fulcrum. The 1/2-inch round
stock passes through 3/4-inch tubing, which is welded to the wing.
The groove between the two hand-holds is needed to keep the wing
from hitting the diver's tow strap as the driver moves the wing
for climbs and dives. One concern I had in the design phase was
that the wing would take the diver up and down too suddenly, but
the hydrodynamics of the prone diver's body is such that even 60-degree
variations in the pitch of the wing produce depth changes at a safe
and comfortable rate. Side-to-side control is accomplished through
a combination of fin work and body English. The diver can swing
maybe 10-15 feet laterally in each direction, but the pull of the
towline "snaps" the diver back to a straight-line, follow
the leader moton.