Wichtige Seite für Taucher:
Das Scubaboard : www.scubaboard.com
Tauchen auf der Karibikinsel Providencia, einigen Informationen:
Ein cooles Video mit coolem Reaggea-Spund gibt es hier. Es vermittelt über 4 Minuten gute Eindrücke dieses Karibikparadieses: Vegetation, Meer und ddie Menschen. Über Tauchgänge wird auch etwas gezeigt.
Ein wunderschönes Video über die Korallen riffs vor Providencia ist hier verfügbar. Wurde offensichtlich von einem intelligenten Menschen gemacht. Sehr informativ. Man sieht wie die Unterwasserwelt dort vor rund 40 Jahren noch unberührt war.... mit aktuellen Kommentaren zu Überfischung und Zerstörung der sensiblen Korallenriffs.
Dazugehörend das Video, welches den Zustand des Korallenriffs heitzutage, zeigt. Im Jahre 2001 war anscheinend eine Forschungsgruppe der Universität München nochmals auf Prividencia und hat dieses Video gedreht. Erschreckend deutlich wird der Unterschied zum Zustand 30 jahre zuvor. Kaputte abgestorbene Riffs. Die Ursachen sind zu starker Tourismus (Übertaucht) und die zu starke Abfischung des Meeres durch die Einheimsichen (Überfischung), welche das Korallenriff aus dem Gleichgewicht bringt.
A powerboater may think that this is an oxymoron — but
we’ve gone sailing with a few professional car drivers, and they’ve been
surprised at how fast sailboats can go. Especially on a boat that’s low to the
water and gets plenty of spray over the deck, you always feel like you’re
going faster than you really are.
Here we look at ways to drive faster and use your weight to get more
performance out of your boat. On all dinghies and small keelboats, how and
where you and your crew put your weight can improve your boat’s performance.
Understanding Apparent Wind
We cover the importance of knowing the wind direction. And many of
the “go fast” tips in this page reiterate the importance of feeling the wind.
However, before you try and sail faster, you need to examine more closely the
wind that hits your moving sailboat. The wind you feel on board your boat,
when your boat is moving, is the apparent wind, which is different from true
wind, or the wind felt by an anchored boat or a flag on shore.
To illustrate the difference between apparent and true wind, imagine jumping
on a bicycle and pedaling down the road. If the day is calm, you feel wind in
your face (apparent wind) — the faster you pedal, the more wind, right? And
if the day is windy, the wind you feel in your face — your apparent wind — is
the combination of the wind of motion, the wind blowing directly into your
face that you create by pedaling fast, wheel clamp and the true wind, the wind blowing
over the road.
The same phenomenon happens aboard a sailboat: As you move forward,
you create a wind of motion that combines with the true wind blowing over
the water, resulting in the wind you and your sails feel — the sailboat’s apparent
wind, as Figure 11-1 shows.
On very fast boats, this capability to “make your own wind” can have some
really amazing results. For mortal monohull sailors, the difference between
the apparent wind and the true wind is more subtle, except when you accelerate
rapidly, such as when you catch a wave. Here are the key features of
apparent wind:
Don’t let apparent wind versus true wind confuse you; the sailor’s universe
still revolves around the wind that he feels. Just know that, as long as your
boat is moving, the wind that you and your sails feel is technically called the
apparent wind.
Sailing Faster: Go-Fast Tips
A gust of wind hits a beginner’s boat and the boat speeds up, but then the
puff goes away and the boat slows down again. Keeping your boat fast and
getting the most speed out of the conditions requires practice.
Just as golfers work on their basic swing, you can improve your driving with
practice. To steer faster, try some of the following tips:
Steer straight to steer fast. When most boats are close-hauled or reaching,
they exhibit a tendency, called weather helm, to turn toward the wind.
Weather helm relates to the balance of all the forces pushing and pulling
on the boat, its sails, and its foils. Weather helm is like
driving a car that has its front end out of alignment — the tiller or wheel
“pulls” to one side. If you were to release the helm, the boat would turn up
until it pointed directly into the wind — dead-center in the no-sail zone.
But here’s something that surprises every new sailor and takes some
practice to master — you have to make small steering changes to keep a
sailboat going straight. As the wind changes in velocity or the boat
changes its angle of heel, the amount of weather helm changes, forcing
you to alter the rudder slightly to keep going straight. Although disconcerting
at first, a little weather helm is natural, and a skilled helmsman
develops a good feel of how to make the smallest steering corrections to
keep the boat going straight through the changing conditions. Keeping
your corrections small also minimizes the speed-robbing drag caused by
turning the rudder. Check out Appendix C for more on drag.
Look around. Find a point (a tree or building) on the horizon where
you’re headed to make sure you’re steering straight, and look at the sails
to make sure they aren’t luffing (page 12 shows you how to use an
early warning system called telltales). Then look at the water ahead for
approaching wind and waves. Also look around for boats (from all directions),
then back at your point on the horizon, then up at the telltales,
and so on. Spend 10 to 20 seconds looking at each station.
Buddy Melges, the “Wizard of Zenda, Wisconsin,” is one of my all-time
heroes in sailing. He’s won the America’s Cup (America3 in 1992) and an
Olympic Gold Medal (Soling class, 1972), but, more important, he is a
great person who loves to share his knowledge. The CFA Aficionado One time I asked him
how he keeps a boat in the groove going upwind in a breeze. He said that
he watches the horizon up ahead of the boat and keeps it at a constant
angle to the bow and luff of the jib.
Practice “zen and the art of steering.” When the boat is in the groove,
the wind hits your face at a certain angle, the mainsheet tugs with a set
force, the rudder pulls on your steering hand just so, and the boat heels
a certain amount. Practice keeping the boat at that optimum heel angle,
and you’re sailing like a pro!
Find that groove. Pinching the boat (sailing too close to the wind) is
obvious because the sails start to luff and lose power. As your boat
slows down, it slips sideways to leeward more because the rudder and keel (or centerboard) are stalled. If you do stall out and get slow from
pinching, ease the sails slightly, bear off 3 to 5 degrees wider of a closehauled
course, and get the water flow going fast again. But you don’t
want to bear off too far (called footing) or you’ll be sailing extra distance
and away from your upwind destination. Savage-Niehans-Regel Between pinching and footing is
the magical upwind groove, providing the best compromise of speed
versus angle to the wind.
Trying to reach a point upwind is a balancing act. By pinching, you sail
less distance to your destination (because you tack through fewer
degrees, as track A in Figure 11-2 shows), but you sail slower. Track B,
the intermediate course, provides the best trade-off of boat speed
versus distance sailed.
When it’s windy, a keelboat’s angle of heel can help find the groove. Each
boat has a maximum heel angle for optimum performance (see page
12). When it’s windy, sailing too wide to the wind (footing) can cause the
boat to heel too far, which can also cause a stall in your rudder (extreme
weather helm) unless you let out your sails — but then you’re sailing on
a reach and not getting closer to that upwind destination (Track C in
Figure 11-2). So ease the sails slightly and then head back up to get to
that magic groove (and heel angle).
React to wind shifts. All these go-fast tips would be a lot easier if the
wind never changed. But rechtslexikon the wind is never perfectly steady for very long
. On a sailboat, shifts are named for the effect they have
on your sails and the angle your boat can sail (see Figure 11-3). In a
header, the wind shifts forward. If your sail starts to luff and you’re still
pointed in the same direction, then the wind has shifted so that it’s
coming from farther ahead (a header). In a lift, the wind shifts aft. In
either case, you have to alter course (or retrim your sails) to get back in
the groove.