On Sun, 09 Dec 2007 19:08:18 -0500, wrote:

On Sun, 9 Dec 2007 16:46:00 -0500, "Wilbur Hubbard"
wrote:


"Marc Heusser" d wrote in
message ...

No personal experience, but maybe the following link might help:
http://www.rya.org.uk/KnowledgeBase/...ntifouling.htm
Not unnecessarily polluting the oceans seems to be a good idea to me.


Here is some idiot who admits to having no personal experience but who must
open his pie-hole as if his ignorant comments have some merit. Then the fool
compounds his folly by concluding with a statement about polluting the
oceans as if one sailboat or all the sailboats in the world combined, for
that matter, make one iota of difference when it comes to "polluting the
ocean" with their bottom paint.

Calculate the volume of water in the oceans of the world and divide by the
totally insignificant amount of bottom paint toxin leeching from yacht
bottoms and it amounts to perhaps one drop of mercury in the Great Lakes. As
if that's gonna pollute anything at all.Time for you, Marc, and all the
other environmentalist nut cases to get real with your irrationality.

Wilbur Hubbard


If all of the yachts of the world were kept evenly distributed over the entire
surface area of all of the bodies of water in the world, you would probably be
correct. The problem is that the yachts of the world are clustered together in
little harbors, nooks and crannies where the effects get concentrated. Shellfish
beds, for one, are not out in the middle of the ocean. They are located in the
same shalow, confined coastal areas where all those boats and yachts are kept.

While Wilbur's calculation is perhaps a bit on the wide side I suspect
that to a large extent he may have the right of it. Studies were
performed at various harbors and problems with shell fish were found.
However, to the best of my knowledge all the harbors studied were
commercial harbors.

Secondly you will remember that initially commercial shipping was
exempted from the ban on TBT, the argument was used that commercial
shipping spends little time in port while pleasure craft just sit
there leaching TBT.

But, I suspect that if the original calculations were to have been
based on area of underwater painted area times hours of exposure
inside the port limits you might have some different results.

A 1,000 foot container ship has a tremendous underwater area. The Emma
Maersk for example is 1302' 6" LOA, Beam - 183' 8" and the draft is
50' 10" while my sail boat is 39' 10" long, 13' 6" breadth and draws
6'.

If you use a simple calculation with port, starboard and bottom as
flat plates (which isn't accurate worth a damn, but will serve to
illustrate my point) then the Emma Maersk has an underwater surface
(loaded) of 371,733.5 square feet. Using the same method, my sailboat
has just about 1,000 square feet of underwater area. Thus for every
one day in port for the Emma Maersk she leaches out the equal amount
of TBT that my boat does in 371.7 days.

I'm sure that Roger could refine these numbers with his computer but
they do serve to indicate that perhaps politics played some part in
banning pleasure boats use of TBT first since pleasure boats seldom
belong to any pressure groups and commercial shipping companies have
tremendous clout in maritime affairs.


Bruce-in-Bangkok
(Note:remove underscores
from address for reply)

Bruce in Bangkok wrote:
....
If you use a simple calculation with port, starboard and bottom as
flat plates (which isn't accurate worth a damn, but will serve to
illustrate my point) then the Emma Maersk has an underwater surface
(loaded) of 371,733.5 square feet. Using the same method, my sailboat
has just about 1,000 square feet of underwater area. Thus for every
one day in port for the Emma Maersk she leaches out the equal amount
of TBT that my boat does in 371.7 days.

I'm sure that Roger could refine these numbers with his computer but
they do serve to indicate that perhaps politics played some part in
banning pleasure boats use of TBT first since pleasure boats seldom
belong to any pressure groups and commercial shipping companies have
tremendous clout in maritime affairs.

With the exception of a few major ports, and especially Navy ports
(which often have dozens of idle ships) I think you might find that
small boats have more surface "in port" than large ships. What I don't
know is where the dividing line is ... where 100 tons ships exempted?

In my home port, Boston, there are very very few 1000' ships. More
typically, there are a small number of 500' ships, most of them turning
around within a day. I was quite surprised the last time I went through
the inner harbor (fall haulout) and there were as many as 8 ships
coming, going, or docked. These ships are at most the equal of 200
pleasure boats, so this would be the equal of 1600 pleasure boats. I'm
guessing there are at least that many boats in the inner harbor, and
maybe three times that number in the extended harbor. Then we can look
at nearby harbors (Scituate, Plymouth etc to the south, Marblehead,
Salem, Manchester, Gloucester to the north) which have many more boats,
but even less ship traffic.