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Boot
Key
Harbor An On-Line
Cruising Guide for the Florida Keys & Cuba |
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Currents USE YOUR BROWSER BACK BUTTON TO RETURN TO THE PREVIOUS PAGE A few issues ago we discussed
the topic of Tides – and how keeping tabs on its level affects our boating
safety in a variety of situations. This month we’ll discuss its counterpart – or
currents. Remember, the tide may be coming
P/C Gregory Absten |
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Boot Key Harbor website created and maintained by Capt. Gregory
T. Absten, Marathon. - A Boater's Guide to the Florida Keys & Cuba |
in but
current is the actual flow of the water. Tides are simply its height. As
discussed in the Tides article, the databases now available at the push of a
button on your GPS make it a breeze to see where you are in the tide cycle.
Remember that the current is flowing the swiftest during the middle of the cycle
between high and low tides, and that at the actual peak of high and low tides
the current flow comes to a stop. If you don’t pay attention this can really get
your attention in some places here in the Keys – like under the bridges and
coming in to fuel or dock. You can get some clue as to the direction and speed
of the current by looking at the water pattern around pilings and buoys. When
its really cranking you’ll see a rounded wave pattern on the up current side of
the obstruction (the direction the current is coming from), and a tail and maybe
swirls on its down current side (the direction the current will set you). When
the current flow slows or stops at slack tide you won’t see any of this. The
pilings under the bridges are a good place to see these eddy patterns. In fact,
all the pilings actually force the current to flow even faster under the bridges
than would otherwise occur, and I’ve seen good sized whirlpools at times. If
you’re passing under a bridge in the same direction as the current you’ll lose
some rudder effectiveness (unless you’re a really fast boat anyway) and will
have to give it some increased speed if you can to help maintain control. If the
current is against you, you don’t have to be as concerned and will have good
steering control. I came under the seven mile bridge once at the peak of the
current, with the current following me. I saw all the huge eddies “downwind” of
the pilings and applied throttle to go through (we do about 8.5 knots). I had a
small boat in tow. As I passed under the pilings the current quickly grabbed me
and flipped me totally sideways between the pilings! Docking can be a similar
problem. Learn to watch the water, read the eddies, and let the current work for
you.