Gary, K4FMX wrote:
"Are you saying that my low (less than 1/2 wavelength high) horizontal
antenna will be next to useless if I live on the sea shore?"

No. Your antenna will do whatever it does. I said that sea water
reflects so well that the reflected ray from the sea is almost as strong
as the incident ray. At low angles they cancel when horizontally
polarized, being equal and of opposite polarity, and this eliminates
low-angle radiation. This is demonstrated in Figs. 13 & 14 on page 3-12
of the 19th edition of the "ARRL Antenna Book".

Low horizontal wires tend to send most energy straight up. This can
provide near vertical incidence contacts.

For distance, when the reflecting surface is good (sea water) and the
antenna is low, the antenna had better be placed vertically. Results are
shown in Fig 16 on page 3-13 of the same book.

Best regards, Richard Harrison, KB5WZI