Weather at sea, a quick breakdown

Getting accurate weather information while you’re underway has always
been of the utmost importance. Whether you’re racing, voyaging or
planning an upcoming trip, knowing what the weather forecast is becomes a
crucial part of that plan. Nowadays, with Internet connections being more
and more common on vessels, getting the weather has become increasingly

Weather via the Internet:
Connections to the Internet can be anything ranging from your everyday
cell phone connected as a modem to your computer, or new FleetBroadband
solution giving you high-speed Internet while crossing the north Atlantic.
Once connected you will find a huge selection of services, both paid and
free, that can provide you up-to-date weather information. A quick search
of Internet weather will return you many sites gathering and interpreting
data from many different weather sources. But what is right for you? What
is going to keep you safest and provide the most accurate weather? For that
you typically rely on paid services.

Weather consolidation services such as ClearPoint Weather or OCENS
WeatherNet take weather information from a variety of different sources and
consolidate the information so that it is easy to use. Small monthly
(ClearPoint) or small per download (WeatherNet) charges apply, but all of a
sudden Internet-based weather is at your fingertips and organized for you
to use.

ClearPoint Weather highlights:
This is the newer of the two programs listed above. It uses a very nice
user interface that gives you the feeling of looking at streaming weather
information. Although it downloads a single file per connection, it has the
similar feel to XM or Sirius Marine Weather (always on, very graphical,
lots of movement and colors). The ClearPoint program is solid and has the
ability to use satellite communication as a means of getting to the
Internet with a low bandwidth setting, allowing you to access their service
all over the world and keep your cost per connection low.

OCENS WeatherNet highlights:
This company has been around for a while now and has been the leader in
providing consolidated weather information to customers all over the world.
It works with races and other events to provide its weather services to the
participants in a manner that has allowed its service to become one of the
favored services throughout the industry. WeatherNet uses an interface that
is geared much more toward getting you the raw data of a low bandwidth
connection (satellite phone). Picking weather files and navigating the
robust program takes getting used to, but when all is said and done, the
huge amount of information is worth it.

Both of the programs highlighted above allow you to download information
and export it in the form of a GRIB file. This is important for weather
routing and overlaying weather information on a chart plotting program such
as Nobeltec Navigation.

Weather via single sideband radio:
Another viable option for receiving weather information is through your
SSB radio. Throughout the day, weather information is broadcasted on
different frequencies from all kinds of different stations all over the
world. From standard surface analysis to spoken synopsis, this weather info
is free to download or listen to as long as you have the right equipment.
When used with a computer or other capturing hardware, you will be able to
download surface analysis, 500-millibar pressure info, and Navtex synopsis.
Additionally, there is a service that actually allows you to download a
daily email containing a GRIB file that can, like the other programs, be
brought into chartplotting software. This can be done with what’s called
a Pactor modem.

Satellite weather:
XM and Sirius Marine Weather are still very much in play. Their services
allow you to capture streaming weather on your vessel through a computer or
chartplotter. Their services are on all the time and data can be accessed
anywhere inside their coverage footprint. This service is not global, but
if you tend to stay in range of the coverage footprint for your everyday
voyaging it may be the right service for you. Simple, easy and it can be
always streaming to your computer. Although a great solution, there is no
current option for exporting GRIB files out of these two services and using
them in a weather routing program. Overlay options are available when used
with a chartplotter or computer system.

To find the best weather solution for you, I recommend taking a look at
your current communication equipment, future needs for communication
equipment, and voyaging habits/plans. Once you have an idea of how you’re
going to communicate with friends, family and/or the office, you will be
ready to make a decision. If you find a need for voice communication on
your vessel in general, your solution for that will almost always come with
a data connection option to the Internet. At which time it becomes a simple
step to pick out the best service for you based on the Internet being your
means of accessing the weather data. Likewise, if your only means/needs
fall upon a single sideband connection, it is also a quick installation of
software and/or hardware to get you weather coming in via the SSB radio.
Many options and variations are available to you and there is no right or
wrong answer.

Please keep in mind, as you search for your perfect weather system, that
one of the most important things is your comfort in using the system.
First, get the training you need to understand how to access the weather
files and get them to your vessel. Second, get trained on how to read the
weather files you’re looking at. Becoming familiar with the terminology
and symbols is hugely important. Look to peers and installers for the extra
knowledge, and if you need help finding a qualified instructor, feel free
to contact me and I can steer you to someone who can help you the most.

About the Author
Noah Hoagland is the owner of Marine Computer Systems in Harpswell, Maine,
which specializes in marine electronics, communications and computer
systems for  sailboats and power voyaging vessels.  Visit him online at

Questions for Noah Hoagland?


By Ocean Navigator