From: "Don Ledger" <dledger@ns.sympatico.ca>

To: AVCAT

Date: Thu, 12 May 2011 13:57:29 -0300

Two observations. This is relatively shallow water if you can believe Google Earth's numbers. not more than about 250 feet at its deepest point on average. Were we to have theresources to side-scan the area thought to be the crash site we might come up with the C-182 Valentich was flying.

Second, if Valentich ditched at night it is doubtful he would have much of a chance to survive a highwing/nosewheel equipped impact.

Under the best of circumstances the airplane would probably have pitchpoled over its nose because of the nosegear. This is considered somewhat desirable with the high wing where once you extricate yourself from your straps from which you are hanging-assuming your head is underwater-you then can get the door open (hopefully) and step out on the submerged wing rather than having it over your head with the plane upright. The latter could be bad at night with the wing acting as a barrier.

Many of us Cessna pilots (more than a few were S&R trained) discussed this in a sort of a macabre way over the years as we debated the best way to tackle this eventuality. The province in which I live is almost completely surrounded by water so crossing the ocean to the "mainland" was always a chore.

I consider the Valentich case one of the most important UFO/UAP events in the last 70 odd years. There was no screwing around here, the man died during the event. The Jose Torres case in another.

Don Ledger

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From: "Martin Shough" <parcellular@btinternet.com>

To: AVCAT

Date: Thu, 12 May 2011 18:12:20 +0100

According to an Australian Marine Research report (Ocean Currents, 1997), Bass Strait is a shallow continental shelf with an average depth of from 50 to 70 m. Tide and wind action results in the mixing of the Bass Strait and the Tasman Sea, causing the saltier, colder (1­3°C) surface waters to sink (downwelling) and fall, much like a waterfall down the continental shelf slope, “beginning midway between Flinders Island and the Victorian coast and extending north almost to Jervis Bay” (Ocean Currents, p. 5). The Bass Straight Cascade pours toward the east.

Tides in Bass Strait “originate from the tidal wave traveling southward down the east coast of Australian. As the wave passes the eastern entrance of Bass Strait, some of its water is deflected into it, slowing down to 80 km per hour in the shallower water. The rest of the wave continues at high speed around Tasmania in a clockwise direction to reach the western entrance to Bass Strait some 3 hours later. The wave front entering from the west meets the wave front entering from the east, causing large tides along a north-south line in the middle of Bass Strait.”

Because of the velocity and force of these currents, it is likely that underwater debris may be carried a long distance. The relatively low mass aluminum structure of Valentich’s Cessna airplane would not sink quickly, nor would it dig into the bottom surface very far as would an anchor or the hull of a heavy ship. It might be possible to locate a particular area where such debris would accumulate over time. Computer simulations should be run to develop estimates of the debris field on the sea bottom, given tides and currents in the vicinity of the probable impact point of Valentich’s plane on the sea surface.

We may never know exactly what happened to Frederick Valentich. Nevertheless, an attempt should be made to locate the airplane. An underwater search should be mounted, despite the 20 years that have elapsed since the event took place.