According to Clive, our
Trailblazer presenter, two obelisks were lined up at a certain distance
behind each other, the obelisque furthest away from shore was positioned
at a higher level. Dutch merchant ships coming into the harbour would
position their vessel, that both obelisks would synchronize to a straight
line.They could then sail safely into the harbour.. Vessels coming
in at night were guided in safely via burning torches on shore using
the same method.The only Portuguese heritage we found were old fortress
walls only a minutes walk from the Dutch V.O.C sea navigation mark.
We were quite pleased to find these small traces of history and are
sure there's plenty more to be discovered and revealed.
Siau - Ulu harbour - Bianca
Venturing volcanoes is
exciting but it reaches its peak underwater. We were curious to find
out more about volcanic activities in the subterranean sea and what
impact it had on the maritime environment. Cruising further north
to the secluded island of Mahengetang, we made some very interesting
discoveries. When diving in the vicinity of underwater hot sulphur
vents or volcanic springs, we noticed that the profusion of hard and
soft corals surpass that by far compared to other locations not being
affected by the volcanic sulphur and thermal factor. We noticed that
marine habitats exposed to the sulphurous substance were far more
diverse, colourful and in some terms more eccentric and abstract in
shape and forms, sometimes well beyond imagination. At these locations
the bio-diversity is so immense that underwater photographers and
marine biologists could write complete new chapters on uncatalogued
critters and other marine life.The underwater volcano Mahengetang
exhibits such an exorbitant flourishing pristine marine habitat. Some
marine biologists who have formerly surveyed and explored this site
are convinced that there are more fish and coral species here within
one square kilometre of sea than in the entire Caribbean Sea. This
location is undoubtedly one of the most unprecedented pristine marine
habitats we have ever come across.The underwater volcano itself is
located just off the island of Mahengetang with the volcano crest
submerged only 2 to 3 meters below sea level. There is no volcanic
crater vigorously churning out lava from the earth's core into the
sea. However, there are huge sulphur covered rocks, which resemble
a crater type formation and vents with intermittent outbursts of volcanic
gasses making their ascent to the surface as bubbles.
Rocks at depth may be hot
at times conducting the earth's heat to the surface. There are no
confined areas here, just a sheer mass of sulphur-covered volcanic
rock gradually sloping into the deep. To the south of the reef, grossly
formed rock pinnacles offered both schools of fish and divers a delightful
swim around. Good numbers of reef fish and pelagics could always be
sighted. A few crevices are exposed to the open sea surrounded and
inhabited by a gorgeous marine botanic. Visibility was always above
average to exceptional, which enhanced our diving motivation and enjoyment.
