|
|
GPS
The GPS is probably the best thing that has happened to sailors since
the invention of the compass. Every blue-water cruiser should have one
and we recommend two. One fixed mounted, powered by the main battery,
and a small, handheld back up, powered by AA batteries.
The Global Positioning System (GPS) is a set of satellites sending
signals to your receiver. When you have contact with two or more
satellites you will get a position. GPS works very well today. When
comparing the given positions to the charts, we have always been right
on. Furthermore, we have not once had the GPS failing on us.
Quality usually pays, but our handheld, cheap back-up GPS has proved
just as accurate as our main unit.
Besides giving the position in terms of latitude and longitude, the GPS
will often also have features like speed over ground, waypoints and
anchorage alarm.
We don’t use all the features but setting the waypoints has been very
useful. You can pull up a display that looks almost three-dimensional,
showing the boat, the course and your deviation from the course. If you
go outside the limits, the GPS give a warning sign. Columbus surely
would have liked that!
The speed displayed from the log mounted under the boat shows only speed
through water. We don’t use it much anymore. Instead, the GPS take in
account the drift and the current and give the true speed SOG (speed
over ground).
There are plenty of good brands around. We use a Raytheon NAV398 as our
basic unit, and a Garmin 12 as back up. They both work great.
Sonar
Sonars
come in all kinds and shapes. The most common send an echo straight
down, this bumping back from the ocean bottom or a big fish, the range
thus calculating the depth.
While this is great in archipelagos, harbours, and the Caribbeans, it is
not really useful when it’s just your little boat and 15000 feet of
water beneath (unless you are checking for whales).
What you want to know is what is in front of you – and as close to the
surface as possible. Containers floating around for instance - hitting
one of those under full sail will sink your boat in no time.
Forward-looking sonar will theoretically give you a chance to detect
containers and other big things close and beneath the surface. If it
works? It didn’t for us. Waves constantly triggered false alarms; large
fish under the boat scared us silly – so we ended up simply turning it
of. But we still thinks it’s great at shallow waters and to check for
fish. The forward looking sonar is also great when approaching shallow
waters in order to estimate approaching ground as opposite to the
grounds already excisting under the boat.
We use a Probe from Interphase Technologies and are happy with it.
Radar
Radar
is great for detecting ships during night sailing (or fog) in heavily
trafficked areas. Even though you just eyeballing can spot the lights
from a ship, it’s almost impossible to judge the distance, or which way
they are approaching. When navigating close to land, the Radar will give
you entrances to harbors or peninsulas that could be hard to discover by
eyesight.
On the Ocean we use the Radar mainly for detecting squalls that could
bring heavy wind, and thus give us a warning for adjusting the sails.
The downside is that a Radar need a lot of power. And we mean plenty.
Your best bet is probably to switch the Radar on for a short while every
hour or so, to scan the area when out at sea. If you have plenty of
power on the other hand, the Radar is a great companion at long night
watches, warning in time for approaching objects.
The Radar we used was a Pathfinder SL70 from Raytheon. When approaching
St. Lucia in the middle of the night at landfall, the Radar failed (the
cursor stopped moving) and we have to navigate through the reefs and
squalls by GPS and Sonar only. While batteling one extra heavy squall,
we almost run into a cliff, and were just seconds from ending our
passage in the same fate as the original Santa Maria.
We sent the radar for repair, got it fixed, it still didn’t work, we
returned it again and eventually got it back in order. We are however
not happy with it yet. The power consumption is huge and it sometimes
fails to notice even large and close ships, no matter how we adjust the
gain (the sensitivity).
The
Radar has a feature that gives a warning sound when a ship or a squall
moves into a certain range. When you are out on the Atlantic in 12 feet
of waves however, the Radar gives alarms either constantly or not at
all.
We had our radar antenna mounted aft, on a 7’ radar mast. Most other
boaters mount their Radar mid-high on the mast and we will probably
change to that position on our next boat.
Log
A simple log is a good thing to have. Don’t buy anything fancy since you
probably will use the GPS for speed most of the time. We have SILVA
digital log with a paddle-wheel transducer mounted just in front of the
keel. When hauling the boat, don’t forget to tell the haulers where the
wheel is placed or remove it altogether.
Our log gave in after two weeks. We sent it for repair but haven’t been
able to get it to work since. Have to admit though that we haven’t spent
too much energy on it.
Compass
Santa
Maria came with an old, large compass mounted on the steering wheel
socket. It doesn’t need any power and feels almost like the heart of the
boat.
We check it for deviation once in a while,
but it is always accurate. Only fault is the compass-light not working,
so we simply use our head torches when steering at night. We also bring
a simple handheld $ 3 compass for emergency.
Autopilot
Santa Maria came with an old Raytheon autopilot. It was attached by a
rubber band stretched from the motor to the steering wheel. When the
winds and the swells picked up, it started to give out high squeaking
noises and a smell of burned rubber. The old AP needed constant care and
adjustments but served well together with the wind vane.
The wind vane worked great in up wind but lousy on down wind. The
autopilot was the opposite. So we found a system working them both
together and didn´t need to hand steer at all during most of the
passage. Several days before land fall however, the autopilot died.

The loss of the autopilot gave us four days of hand steering at the end
of the passage. It was hard since we were only two, but also awarding
since it forced us to look more intensely at the sky and the sea.
We had brought a brand new autopilot unit with us as a back up. This one
we mounted on St. Lucia and have used it since. It hasn’t been tested in
storm yet but seems to work fine.
It’s a Raytheon ST4000 and is said to be a little too weak for a 37 feet
boat. The next step up required some additional 5000 dollars however, so
we decided on it anyway. The electronic display is very simple and
useful. It is silent and doesn’t use a lot of power. Actually, we
haven’t even had to use the wind vane since we installed this AP.
Wind wane
For
a small crew crossing the Atlantic, a wind vane is essential. The main
difference between a wind vane and an autopilot is that the autopilot
will be true to the compass and the wind vane true to the wind. There is
an ongoing debate regarding which is best. Our experience is that the
wind vane will work best and give you less hassle in up wind, while the
autopilot will work better in down wind.
The wind vane is useless in light wind and work better the more wind you
have. In high wind the autopilot may burn and/or stop working. When the
wind direction changes back and forth, the wind vane will give you a
smooth and sail-effective ride, compared to the autopilot.
There are different kinds of wind vanes.
The one used at Santa Maria is an auxiliary rudder fitted to the stern
of the boat. Attached to the rudder is a wind vane made of sailcloth.
You operate it by steering the boat to the desired angel of the wind,
climb to the aft and tighten the wind vane in the position it has at
that wind angel. Often you´ll have to do this a couple of times before
you get it right.
When the wind force changes, you´ll have to adjust the vane again. Our
wind vane is not as smooth as we would like it to be. Attaching a small
trim tab at the back of the auxiliary rudder would probably fix that.
Most blue water cruisers use a servo pendulum unit. It is a masterpiece
of mechanics and will surely bring out the kid in every captain. While
at the Canary Islands, we had a French family preparing for the crossing
next to us at the dock. During the entire week, the husband never
stopped adjusting and making improvements to his very dear servo
pendulum unit.
Instead of a sail, this vane uses a lightly balanced piece of thin
plywood for catching the wind. The boat is set on course and the vane is
aligned with the wind and then fastened. When the wind push the vane
from either side, it will bend down. A servo-rudder will then change the
course to the desired. We don’t have any hands-on experience with these
units, but have been told that they work very well – probably even
better than ours.
Laptop
There are marine designed laptops around. Stored well however, your
regular office lap should be sufficient. Get a DC power adapter.
|
|