Making a pass
CuriousOyster
Steve & Trish Brown
Sat 1 May 2010 21:45
|
Having run through a couple of passes into the
lagoons I am now beginning to understand why they can be so
difficult.
Not only is there a lack of accurate tide data for
each Atoll, our Navionics electronic charts not only have the wrong times but
also show high tide when it is low and vice versa. If ever there was a place
when you needed accurate tidal information it is the Tuamotus.
Because of this problem we came through the pass
into the Manihi lagoon at the wrong time and although the currents and eddies
posed few problems we passed over the coral bar at the inner end of the pass
with no more than 0.5 metres under the keel. Clenched buttocks all
round!!!
 To add to the difficulties the Atolls have very low
lying outer reefs, some times no more than a few inches above sea level so that
sea water is washed over the reef, constantly filling the lagoons. In windy
conditions and moderate sized seas this adds a considerable volume of water and
can create a constant outgoing flow even when the tide is supposedly incoming.
This churns up the water in the channels, complicated still further when the
outgoing flow meets the semi static sea outside the atoll creating back currents
at the sides of the pass.
 To compound this madness we decided to do a drift
dive through the pass at "slack water" to get a better look at the thousands of
fish and sharks that feed in the strong currents. Having observed the tides and
currents for a few days we were confidant that we knew the best time to make the
dive and waited for the wind to drop. Having buddied up with a Danish boat, six
of us dropped into the entrance to the pass at the inner end of the lagoon to be
gently swept through towards the seaward entrance. At least that was the plan.
The channel was teeming with all kinds of fish and black tipped reef sharks and
as per our plan we were gently carried with the current towards the shallow bar.
As we approached the flow increased considerably to the point where it was
impossible to swim against the current and we had no option but to be carried
with the flow, ever faster and upwards from 16m to 4m as we passed over the
coral bar!
What a ride!!
Once through the current eased sufficiently to
enable us to swim towards the outer edges of the channel into calmer waters. All
except one young Danish girl who could not get out of the current and was swept
out to sea. Fortunately we had positioned one of our group in the dinghy's to
follow our progress and he was able to motor out to pick her up. A fantastic
experience and another lesson in the power of nature.
|