Wednesday, 19 June 2013

Email Systems for Blue-Water Cruisers

Hi everyone,
For some time we've been considering whether HF is the most cost-effective means of sending and receiving email from Zen Again.  We don't need to browse the internet, but we do need to be able to download weather information in the form of GRIB (or similar) files.  Apart from GRIB files we only need plain text email.

We've used HF email for many years and it has worked well for us.  But it does have some disadvantages:
  • Purchase cost of Pactor-3 modem ($1500) or Pactor-4 modem ($2000+)
  • Purchase cost of modem is on top of cost of the HF transceiver ($1500-$3000)
  • Running cost $250 per annum using SailMail, or $0 for Licensed Amateurs using Winlink
  • Limited number of coast stations in the Australasian area
  • Variable propagation conditions depending on time of day and other factors
  • Non-trivial learning curve to optimise HF system and its use for email
  • Requires planning, effort and sometimes luck to successfully send/receive emails
  • Need to actively connect to a coast station to check for emails - maybe twice a day max - with each connection taking more than 15 minutes in marginal propagation or busy conditions
We've looked at satellite phones several times over the years, but for our email needs they too have disadvantages:
  • Purchase cost $1000-$1500
  • Running costs (voice or data) around $1 per minute
  • Data rate limited to 2400bps
  • Data connections prone to drop-out
  • Often requires external antenna to make data connections workable
  • SMS/texting cheaper but size limit too small, and no GRIBs of course
Recently we found an alternative.  At last!  We discovered the PredictWind Satellite Communicator.

Satellite Communicator (at home)
The Satellite Communicator uses the Iridium Short Burst Data network and integrates a GPS and ZigBee wireless link to a PC or Mac running PredictWind's email software.  The advantages of the unit from our perspective are:
  • Cost-effective (similar or cheaper purchase and running costs to the alternatives)
  • Always on
  • Low power (0.05Amps in standby, 0.2A transmitting)
  • Very simple to install
  • Very simple to use
  • Tracker function transmits position hourly to PredictWind regardless of PC/Mac connection
  • Plain text email transmit & receive
  • Any plain text (weather, news & more) such as from SailDocs is retrievable
  • Weather routing service from PredictWind (requires Professional package)
The Satellite Communicator needs further development to maximise its cost-effectiveness.  The most important is provision of GRIB files (subject to Iridium SBD size limits).  Here are the features we'd like to see:
  • Provision of GRIB forecast and GPX route files instead of current text-based routing
  • Email client very basic (eg can only add/delete contacts but not modify, can't create folders etc)
  • Iridium and GPS signal strengths not available on PC/Mac
  • GPS data not available on the PC/Mac
  • Tracker messages not copied to PC/Mac (would confirm they're really happening)
PredictWind costs may seem a little high at first glance, but it's worth noting you can move between the Basic, Standard and Professional packages as often as desired.  This should make the running costs similar to SailMail for many cruisers since one only needs Professional when on passage.  Normal email works regardless of whether you have a PredictWind subscription or not.

So far we've only been testing the unit at home here in Perth but are very pleased with what we see so far.  The unit is far easier to use than HF email.  In our opinion it's worth a look if you want email aboard your blue-water cruiser.

As soon as GRIB and GPX files can be retrieved the Satellite Communicator will be a far better solution than HF email.  In the mean time I have a workaround which delivers PredictWind GRIBs and GPXs to our unit after a little intermediate processing!

ps - We have no association with PredictWind save being a satisfied customer!







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