I would say the difference is:
a. is from a book
b.is from the real world (experience)
the number of vendor specific IT courses where the teacher has said "to pass the exam answer a. in the work place answer b. grows yearly
You appear to have missed an important point. It is not my computation, it is United States Navy
Commander Brandenburg's computation. He computed that the height of the tide was 9 inches at 2100 Z, only one-half hour after the Lambrecht overflight. This is 43 inches lower than the height of the reef surface where the Electra is supposed to have been sitting which is at 52 inches above the tide datum, again by Brandenburg's computation. This 9 inch tide height is also only
ONE INCH above the height of the edge of the reef, again by Brandenburg's computation. The only "computation" that I did was to INCREASE the height of the tide by 4 inches, up to 13 inches, to allow for the fall of the tide in the half-hour period from the time of the flyover to the 2100 Z 9 inch tide height computed by Brandenburg. This 4 inch change in the tide is the same as the 4 inch change in the height, down to 5 inches, one-half hour later at 2130 Z, again, as computed by Brandenburg. Based on your expertise in tidal studies, please explain how the tide fell only
4 inches in the half hour period between 2100 Z and 2130 Z, as computed by Brandenburg but managed to fall
67 inches (a 17 times greater rate) in the immediately preceeding half hour period between 2030 Z and 2100 Z as required by Ric's claim that the tide was two feet above the reef (76 inches above the datum as computed by Brandenburg) at the location of the plane at 2030 Z, the time of the flyover. Please
read what Brandenburg has written about the tide heights and look at
HIS diagram of the reef and the datum. After your review you should see that the tide heights do not rely on my expertise (though I have been a sailor for almost 50 years and have had to work with tide tables and charts in order to sail deep draft boats through shallow passes through reefs in the South Pacific and other oceans) but are based on Commander Brandenburg's Navy officer's experience and expertise.
(BTW Chris, as long as we are at it, what is your expertise in these matters?)
gl