Here is SaltyMonkey's summary report. Please feel free to let me know corrections and addendum comments that might make this more true and clear.
state of remote telecommunications on a sailboat to access the internet
particularly for email and downloading weather
information is not necessarily leveraging the latest technology that you might find on land. The affordability of access is expensive when services and hardware
are taken together, and access is slow and cumbersome. There is no affordable small dish solution such as HugesNet or Wild Blue, that is available on a small craft. Most small craft are using a combination of SSS/HAM radio, Satellite Phone
, and Shortwave Radio to retrieve weather information.
Although there are various sources of content for weather, a few important observations and definitions clarify needs:
WEFAX - Radio weather fax is the most useful source to collect weather information and should be a default standard for gathering weather information on a small craft. GRIB files that are based on model are not as accurate between 25 deg N/S, so if you are cruising in this area, you should use WEFAX as a primary source. if you are crusing at higher lats, WEFAX can serve as a confirmation to using GRIB files you might retrieve. WEFAX forecasts unlike GRIB based models are constructed by human technicians using a variety of sources including models and observations.
GRIBS - GRIB files are really just a compression
file format that is used to send weather information. However, most sailors when speaking of GRIB files are using them as a synonym for the following major weather models:
- GFS model from NOAA
- WW3 model from France
(Wave Watch 3)
Some important points:
- GFS model information tends to be more accurate forcast than WW3 and is preferred first. Accuracy can be requested to .5 deg resolution 2x2deg is the default. WW3 is 1x1.5 deg resolution,
- Ocens, Saildocs use the GFS model for their GRIB files
and the GMN GRIB Robot uses WW3 model for their GRIB files
Closer to land additional models known as "mesamodels" are available. These tend to be useful to approx 20 nm offshore
. Beyond this, GRIB models are more useful to a cruiser. These mesamodels include:
- COAMPS - US Navy
- NOGAPS - US Navy
Additionally, raw wind
data is available via QSCAT (Quickscat). This raw data is used to feed the GFS model.
All models are available via SailDocs (see below). WEFAX images
and forecasts are also available through SailDocs. It is unclear if WEFAX images
can be delivered in GRIB compressed format.
Weather Service Providers
There are a number of subscription companies that provide commercial
weather model information. Most of these rely on the GFS model to derive additional projections and details. Some models also incorporate raw wind
data in these calculations from QSCAT. These subscription services also provide course corrections to the subscribers if they are sailing, to best take advantage of course - safety
Examples of services include:
- PredictWind Wind Forecast, Marine Weather, GRIB, Marine Forecast, Wind Prediction
- Commanders Weather Service Commanders' Weather
- Weather Routing Inc Weather Routing, Inc. (WRI)
- Ocens WeatherNet OCENS WeatherNet - Weather On Demand
Most cruising sailors do not use weather routing services or commercial
weather providers, but rely on their own software, downloads via FREE services, and rudimentary knowledge. There is some question as to the reliability
of the forecasts and routing of commercial providers, as well as the need for such accuracy way offshore
. Moreover, it can be expensive.
There are some navigation
software packages that will allow you to calculate optimal routing using weather information. Once such package is:
- Expedition - Expedition
- MaxSea Time Zero - Marine Software
WeatherFax (WEFAX) Weather Retrieval
An affordable and simple way to retrieve weather information is to connect a laptop
to an all band short wave radio, using an external antenna
to download WEFAX images and data to your hard drive for viewing. WeatherFax 2000 is a software package that can be used with the computers
microphone jack port to digitalize analog signal information from a stand alone radio. As a basis, having this setup is useful as an emergency
in case more sophisticated communication systems fail.
The second option is to get a stand alone FAX/NAVTEX receiver, such as a FURUNO
FAX30, and connect it to your chartplotter
An SSB radio can also be used to tune to broadcast. Both WeatherFax 2000 and Airmail's companion product GetFax and ViewFax will allow you to remotely tune and retrieve WEFAX via your SSB radio automatically.
WEFAX images are also available using the SailDocs server as a conduit to retrieve forecasts and TIF/GIF files from NOAA. It is unclear if these images are also available in a GRIB format from SailDocs.
GRIB Models Retrieval
GRIB stored models are available for free through various servers, and delivered through email to the user. Most users make a request to saildocs or GlobalMarineNet.com (http://www.globalmarinenet.com/publications/grib.txt
) using commands in the body of emails, after reviewing catalogs from previous downloads. Catalogs and requests are available through software email clients as well
SSB or Iridium (Sat Phone) for Email (and GRIBS)
For email, either a SSB/Ham station must be set up or you need to use a sat phone
, each has its attractions and negatives. Both demand compression
- no competition for bandwidth or frequencies with other cruisers
- no email limitations per week (90 minutes for sailmail)
- always available (no dark areas in PNW for example)
- direct dial for emergencies
- separate power in case of rolling etc.
- easy installation
- ability to disconnect from distractions and other cruisers.
- no local communication around the yacht.
- costly per minute plans
- no step capability during downloads. Any fluctuation disconnects the call.
SSB/HAM Station, Tuner, Modem (soft or hw), Antenna, SailMail/Winlink, Fax viewer:
- Annual service is FREE (ham) or $250 a year
- Step capability of modem allows for files to be transferred in noisy conditions.
- Modem is theoretically faster downloads (higher baud rate) than phone.
- Communication device can be used to verify weather with other cruisers, as well as other passage
- Costly hardware including modem. WINMOR soft modem may not be reliable enough for offshore usage.
- Complicated setup
- Dependent on battery
power which is not good in a swamp or roll.
- Not available worldwide. Problems in PNW for example
Both SSB or Sat Phone can be used for Ship to Shore phone calls for about the same price
Outside of the Pactor III based modems, Its questionable whether the other modems are faster than iridium given there are also software compression algorithms involved.
Pactor I - 140 bps
Pactor II - 1200 bps
WINMOR - 2167 bps
Iridium - 2400 bps
Pactor III - 5200 bps
- 9600 bps
Salty Monkeys Ham Shack
SaltyMonkey, being solo, probably should bite the bullet and get as many configurations as possible for safety
and backup. Since he is headed to all latitudes, SSB alone is not enough. Iridium alone would not allow him to get other important cruising information from other cruisers and ships. SaltyMonkey also likes to be a ChattyMonkey so being apart of a community as he potentially sails
his boat from SF to Sydney
non-stop would be helpful and stop him from talking to himself. Those first few days at sea are psychological hell.
Systems for SaltyMonkey then...
- Backup WEFAX weather System using WeatherFax 2000 and all band shortwave receiver with antenna. This should be mandatory.
- Iridium phone, GlobalMarineNet/xgate - call home; high latitude sailing downloads; emergency
- SSB/HAM radio ICOM
802, PCT-II usb modem w pactor III upgrade, Winlink service, get fax/Faxviewer, airmail.
- SailDocs - leverage for both Iridium and SSB
- MaxSea or Expedition software for instrumentation, navigation
, and voyage routing based on weather analysis.
SaltyMonkey will also bite the bullet and go get his HAM license
. For years he had been holding off, but now it makes sense.