Sent: Sunday, August 03, 2003 10:50 PM
Subject: Songkhla and Transmissions
As expected, we are delayed in Songkhla for a few more days. I am having
trouble with the transmission and spent the better half of a day fiddling
around with it to the conclusion that I need a professional mechanic to
take it apart with me. I have one coming to the boat this afternoon and
we'll see what we can do. I don't think it is all that serious but you
never can tell.
Most other business is completed and we are ready to go otherwise. I still
need port clearance but the harbor inspection aspect went so well that
I expect little problem with this as well as the immigration issue. I
think it will just take a few hours and then we can be off. Unfortunately
I can't take care of it until we actually CAN be off. Once the port clearance
is received we need to be out of port in under 20 hours so that will be
my last order of business.
There was another topic which I wanted to write a little on. As we sailed
down the coast, I, for the first time noticed the difference between optical,
visual and geographic horizon. It was a topic we covered in my coastal
navigation class which, as with many topics, I understood but not actually
witnessed. It was taken in but not seriously processed.
Most of the coastline of some 150 NM (nautical miles (just over a regular
mile)) from Samui, south to Songkhla and further south to the border,
is incredibly flat with no mountains and little elevation above 10 to
15 feet. It is a long straight coastline, which lies very low. It is new
to me. I have never sailed along a coast like this.
As we sailed south and I watched the horizon ahead of us, low trees would
slowly appear and then some fishing boats and houses. These things appeared
as out of a mist or haze and I would define this as the "visual horizon"
which was limited by the particulates in the air.
Then a few squalls blew through and everything became much more clear
and crisp. The visibility increased quite a bit. Then watching the horizon
I noticed that very small bulbs of trees would pop up out of the horizon
not unlike water collecting and forming a droplet, but upside down. It
would appear as a small flat dark color, then suddenly burp into an upside
down drop hanging on the surface of the sea and earth. It was still surrounded
by the water of the horizon at it's base and I must suppose that this
was a result of some optical refraction which made taller object on the
geographic or optical horizon appear as upside down water droplets with
a pinched base. Slowly the base of the bubbles would widen into bunches
of taller trees and then houses would appear and so on.
I have witness the curvature of the earth in other ways but this was a
new one for me. It was made more fascinating because I already knew about
it but had never witnessed it. It seems pretty ordinary when I read back
over my navigation books, but it was very entertaining to see it in reality.
I have not been on many coastlines that are this flat and long. I believe
if there are any kind of mountains or islands, their geographic range
is so very far that there is no way that the visual range will be farther
than the geographic range. Only items very low on the horizon with no
background might have a geographic horizon shorter then a visual horizon.
I think a sailboat at sea might have this effect, which is something our
friend Columbus witnessed.
The wind has been howling offshore and is perfect for some brisk coastal
sailing but as I explained above we are stuck for the moment. It seems
the winds like to blow just as we desire while we are in port, but get
all crazy and unpredictable when we pull out. I hope this wind keeps up,
as it will lend to a nice fast trip to the Perhentians.
I will write again, at least before we depart.
Hope all is well at home.
Dad, good luck with the visa for Galyani.