On Thursday, October 05, 2000 3:08 AM, Ray Cardinale wrote:

> Funny this should come up. I have experienced an underwater charge
> (Ash Can firecracker tied to a rock) detonated approximately 6 feet
> away. It caused me to be knocked over backwards and startled but
> other than that no permanent affects. My question to you and any
> others is have you ever had a similar experience with underwater
> explosions.. small or large and what were the circumstances?

My very first experience happened long ago!  :-)

An easy 'recall' system for divers on underwater exercises was to surface
whenever you heard a series of 'bangs' - as hitting the boat's diving ladder
with a heavy hammer - or a single bang when thunderflashes were used.  (A
thunderflash is a cardboard wrapped powder charge used to simulate shell and
mortar explosions on exercises - or just to scare the bejesus out of anyone
in the vicinity.  They can be quite devastting in confined spaces.)

As an energy saving device, thunderflashes were quite often the preferred
method of recall used by Petty Officers supervising the dive.  A small piece
of lead was wrapped around the base as ballast.  The fuse was ignited by a
striker plate - a similar method as that on the side of a box of matches -
and the thunderflash lobbed over the side.

I was wearing a 'body-bag' dry-suit that was nicely crimped to the contours
of my body as I vented gas from the sleeve during an ascent at the end of
the dive.  As I rose gracefully through the water a fizzing thunderflash
drifted down in front of me.  "Oh, bugger!"  I thought as I began to peddle
my fins.  It exploded a few feet below my crutch!  It was not one of life's
most enjoyable experiences.  Neither did it do much for my singing voice!
:-)

They then progressed to using 'scare' charges in training scenarios.  Where
the presence of an underwater enemy was suspected, ships' boats would circle
an area lobbing these charges into the water.  If one landed close by a
diver then it would certainly render them senseless - at least!   Even from
a distance of, say, 100-metres the shock wave was considerable.  But at
least you could claim afterwards not to have heard the Chief Petty Officer
calling out, "Where do you think you're loping off to, you 'orrible little
gobshite?  Come back 'ere and get back in the water."!  :-)

Strike