goes for the fishes, too, and there’s even an
endemic species of pygmy seahorse that’s
found only in this area.
The island is surrounded by this sort
of dense, high-diversity reef, and you can
easily snorkel out to it at high tide. As you
snorkel along the top of the reef the water
gets a little deeper and the reef crest drops
down a bit, then there’s a pretty steep
dropoff down to deeper waters, with the
bottom being at about 5000 feet in some
parts of the park further out from the
island. Most of the diving I did was at less
than 60 feet, though, which is fine with
me, as that’s where most of the good stuff
is to be seen. When you’re diving, your air
lasts longer at shallower depths, too. That’s
a good thing when I’m trying to take as
many pictures as possible on each dive.
Still, with all this in mind, the thing that
was really the icing on the cake was the
spring tide that occurred while I was there.
I got the dates right, and was glad to have
done so. The oceans rise and fall every
day, which we see as tides. However, the
amount of rising and falling changes from
day to day, and also from month to month.
When certain conditions fall into line the
tides fall the greatest amount, and this
event is called a spring tide.
The cause for this is a certain alignment
of the Earth, Moon, and Sun, as the Sun
gravitationally tugs on the Earth, and
the Moon does, too. You’d think the Sun
would exert the greatest pull, but it’s so
much farther away from us that the Moon’s
pull is actually stronger. After all, the Sun
is about 93,000,000 miles away, while the
Moon is only about 240,000 miles away.
Anyway, when these celestial bodies pull
on the Earth, the seas directly underneath
them rise up slightly as a bulge. And the
Earth is turning at all times, of course, so
the bulge seems to move across the surface
of the Earth in bodies of water. And
the Moon is always moving around the
Earth, as well. Oddly enough, following
the laws of physics, an equal size bulge
rises on the exact opposite side of the
Earth, too, and the locations in between
these two bulges experience low tides
simultaneously. Sounds a bit complicated,
but I’m not done yet.
All you need to think about is that the
pull of the Moon and the Sun is ever-changing, since the Moon is behind the
Earth with respect to the Sun at some times
a perpendicular direction (when the Moon
is next to the Earth), and there are times
when the Moon, the Sun, and the Earth are
all in a roughly straight line. When they all
line up like this, there’s an extra-high tide
of the month, is next to the Earth at other
times of the month, and is in front of the
Earth at still other times of the month.
Therefore, there are times when the Moon
is pulling one way and the Sun is pulling in
Not only were there numerous gorgeous tridacnid clams in shallow water, there were many
exposed to air, too, during the spring tide (the clams tend to close up tightly during such exposure,
however, so there are no pretty pictures of them out of water).