Re: Pontoons

[SFreihof@aol.com]

In a message dated 8/16/99 2:10:40 AM Eastern Daylight Time, 
snyde032@tc.umn.edu writes:

<< His argument is that somehow, the heavier the boat, the more force is 
required to lift the pontoon, since the weight of the boat is pushing down on 
the float. >>

I think you're both right because the pontoon will displace water equal to 
the weight it is supporting.  The heavier the boat, the deeper the pontoon 
will ride in the water (the more water it displaces), thus the further 
underwater the hole is, thus the higher the ambient pressure.

The point is that the weight of the boat is only relevant to the extent that 
it drives the pontoon's hole deeper underwater.  Because of the hole, the 
pontoon is an "inverted glass".

But regardless, his pontoon is not designed to hold compressed air, which 
makes his plan very risky.  At best, his solution requires that the hole be 
in the very bottom of the pontoon, which may not be the case.  Compressed air 
will only blow water out until the air reaches the level of the hole... then 
bubbles will escape, not water.  But then you'd know where the hole is.  

What seems more likely to me is that the pontoon is sinking until the level 
of the water inside the pontoon covers the hole... in which case no more air 
can get out, and thus no more water can get in (i.e., inverted glass).  
Pressurizing the pontoon will not help.

That's my 2 cents.  Keep the change.