By Daniel Piltch and Tim Hasson, Marine Computer Systems
(as originally published in Ocean Navigator)
Going to Sea and Staying in Touch
So, you’re planning to spend a long time at sea, and are wondering how you’ll be able to get your email while you’re cruising. While this still isn’t as easy as it is on land, it’s becoming easier to do each year; and this year is no exception with several new or improved products on the market. We’ll take a look at how the tried and true method of sending email over a single sideband (SSB) radio has been improved, and we’ll also take a look at SkyMate – an alternative email system that’s quickly gaining in popularity.
Sending data over the airwaves actually pre-dates the invention of email! In fact, it was Mr. Joy Morton (head of the Morton Salt Company) who put up the financing in 1902 to enable Charles L. Krum to patent his Radio TeleTYpe (RTTY) invention. Initially, the idea consisted loosely of two typewriters connected via a telegraph cable – what was typed in on one appeared on the other after being encoded and transmitted over the wires. In the World War II era, this same idea was applied to the burgeoning high frequency radio technologies to enable the transmission of data wirelessly over radiowaves. Somewhat surprisingly, this initial wireless RTTY technology is still in use in many parts of the world to transmit text weather forecasts. Later improvements resulted in the SImple Text Over Radio (SITOR) protocol which is able to send data at what now seems like the sluggish rate of about seven characters per second after accounting for overhead and error correction! While it sounds slow to those of us accustomed to cable-modem connections and DSL lines, this proven technology is still used today to broadcast NAVTEX bulletins and weather advisories to ships at sea by maritime authorities around the world.
In the late 1980s two German amateur radio operators invented a new protocol which they named Pactor (Latin for “mediator”). The first version of Pactor improved many aspects of transmission, but speeds were still in the 7 to 14 characters per second range.. A later revision, Pactor-II, improved things significantly and brought speeds up about 100 characters per second – a truly revolutionary improvement, given that errors in data transmission were largely eliminated as well. Along with Pactor-II, a compression scheme was developed allowing effective speeds of up to around 140 characters per second, depending on the data being transmitted and, perhaps more importantly, the quality of the radio connection at any given moment. Unlike it’s predecessor, Pactor-II was kept as a proprietary standard and is available only by license from Specialized Communications Systems, GmBh, the creators in Germany. Despite it’s proprietary nature, Pactor-II became the de facto standard beating out other competing protocols such as G-TOR, THROB, HELL and other less provocatively named systems. Because Pactor-II was privately controlled by SCS, they were able to build a business selling modems licensed to use the Pactor-II protocol. The current generation of SCS modems are the $699 PTC-IIex and the more powerful PTC-IIpro ($1049).
In late 2001, SCS again improved upon their now-standard protocol and created Pactor-III – capable of speeds as high as 640 characters per second (with compression). While these optimum speeds are achieved only under ideal radio operating conditions, they represent a significant improvement over earlier versions. Pactor-III is also a somewhat more robust protocol, able to maintain a radio link when the going gets tough on the SSB airwaves. For reasons like these, Pactor-III has quickly emerged as the protocol of choice among providers of SSB email services to cruisers.
Though Pactor-III is a newer protocol, there is no such thing as a PTC-III modem to replace the PTC-II models. What SCS have done is to allow both PTC-II modems to be upgraded to be Pactor-III capable simply by flashing the firmware inside the modem (for a $150 fee). So a new PTC-IIex modem, upgraded to work with Pactor-II would set you back $849 ($699 + $150), and a PTC-IIPro with the upgrade would cost $1199. You’ll also likely want a pre-made cable to connect the modem with your radio ($42 for the Icom M710/M802 compatible cable).
The modem sits between your computer and your SSB radio – relegated to the task of encoding your email messages for transmission over the air, and of decoding incoming signals back into text. The last piece of the email over SSB puzzle is the coast station or service provider.
SSB Email Service Providers
SSB Email Service Providers are the companies and organizations who operate networks of coast stations to transfer your messages. There are a dozen or more of these operations spread around the globe – some are regional operations, while others aspire to truly “world-wide” coverage.
Those with a General Class or better amateur (ham) radio license can make use of the WinLink network of coast stations, which is generously operated by a worldwide network of amateur volunteers. WinLink is a free system – no sign-up fees, no monthly fees, and no usage fees. Other than the ham license requirement, the only other “catch” is that the system cannot be used for commercial purposes (you can’t use the system for profit-making ventures). This restriction arises from the way amateur radio operators are licensed, not WinLink..
In addition to plain text email, the WinLink network offers other enticing benefits. The service offers a catalog containing hundreds of weather products that can be requested via email including weatherfax charts, text forecasts and GRIB models from around the world. It is possible to send attachments to an email via WinLink, although there are some practical considerations given the nature of the slow-speed connection. A position-reporting feature lets users file brief updates via email which will then plot the vessel’s time, position and a brief comment on a graphic map which can be viewed on the Intenet by anyone who knows the vessel’s amateur call sign (see graphic).
An alternative to WinLink for the non-ham sailing community is SailMail. This is a non-profit organization, founded by sailors, that uses its annual dues ($250 per member) to fund the operation of its network of about fifteen stations around the world. No amateur license is necessary to join, though you must have a proper ship station license and call sign. In the US, this would come from the Federal Communication Commission (FCC). No test is required to obtain the license, but you do need to fill out the forms and send in appropriate payment. SailMail users are limited to 10 minutes of use per day – more than adequate for recreational email use.
SailMail users can use an associated service, called SailDocs, to retrieve text weather forecasts. Email attachments are not supported, with the exception of small GRIB weather files. Both the WinLink and SailMail systems use the PC-based AirMail software as the email client. Written by veteran cruiser Jim Corenman, AirMail is straightforward to install and use, and can be downloaded from the Internet at no cost (www.airmail2000.com).
There are other service providers, including WLO Radio in Mobile Alabama, CruiseEmail in Florida. The stations operated by Florida-based MarineNet radio were off the air as of this writing, but service may resume in the future. A comparison chart on our web site at www.marinecomputer.com summarizes the capabilities of most of the North American service providers.
A rising star in the world of email at sea is Virginia-based SkyMate. Led by former Orbcomm Chief Technology Officer, John Tandler, SkyMate is a satellite based rather than SSB based email system. The hardware consists of a silver box dubbed the SkyMate Communicator (about the size of a small paperback book), a 38” stainless steel whip antenna, and your own computer. The $929 purchase price, includes everything you’ll need to get up and running – except of course the computer, which you provide.
In addition to the standard text emails that the SkyMate system features, you also have access to a significant amount of weather information (including text forecasts, real-time weather buoy information, radar imagery, as well as weather charts from the National Weather Service). Other added features are the voice and fax capabilities. These are both one-way services that enable you to create a text based message which is then either faxed to the number you designate or read in a computer generated voice to whoever picks up the phone after dialing the number you specify.
Once you have the unit installed, you’ll need to sign up for one of three service plans (Silver, Gold, or Platinum) ranging from $16 to $70 per month. Service is billed according to the number of characters transmitted and received in a given month. Each plan includes a certain amount of “free” characters, and a charge per 1,000 extra characters transmitted or received beyond the free allotment. Plans can be changed at will each month, and your account can be set aside for inactive months by switching to a special Dry-Dock plan ($4.99 per month) which maintains your email address (and the ability to check it using the web based interface) until you decide to reactivate.
A popular feature of SkyMate is its position reporting ability. By hooking up your vessel’s GPS into the SkyMate Communicator, you can generate position reports which are sent to an email address (or several addresses) of your choosing. You can also designate the frequency with which these position reports are sent – perhaps once a day, or once an hour depending on how anxious your shoreside followers are. By providing these folks with an id and password, they’re able to view your location on a Maptech chart over the Internet.
The SkyMate package is also available in two “deluxe” models – SentryMate and Tracker. The SentryMate package ($1,229) adds a bilge level sensor as well as shore power and battery level sensors. The information is collected and emailed to you on a regular basis – you choose the frequency and the email address. The Tracker package ($1,369) adds an internal GPS into the Communicator box – alleviating the need for you to wire in your own GPS for position reporting.
SkyMate’s software (included in each of the above packages) is a testament to thoughtfully designed, easy to use interfaces. The screens feature large buttons with clear functions. It’s very difficult to “break” the software. We’ve done it, but it’s rare. This is one of only a few marine software packages that is easy to learn, even for a novice computer user.
Most problems we’ve seen with SkyMate systems can be traced to the antenna system. Improvements have been made from a larger fiberglass whip which was susceptible to internal damage when bended, to the now-standard stainless steel whip which seems to be more rugged. A loose connector on the antenna cable can have serious consequences, with messages not being delivered as intended. Fortunately, this is easy to diagnose and easy to fix. The software includes a system statistics screen that indicates how well the system is communicating with the satellites overhead – a boon to troubleshooting antenna problems.
SkyMate uses a store-and-forward messaging scheme, meaning that messages may not be transmitted instantaneously when you press the “Send” button. Rather they’re stored in the memory of the SkyMate box until an appropriate satellite is in view – the message is then sent on to the satellite for onward delivery. Inbound messages are similarly routed to appropriate satellites. For most of SkyMate’s coverage area (most of the world except for the South Pacific and waters near southern Africa) a satellite would be in view within 5 to 20 minutes of any given time.
This system is not for the power email user, as attachments are not allowed, and there is a maximum limit of 5,000 characters per message. This is more than enough for even the most loquacious of ship’s log entries, but might fall short for the business user sending large documents back and forth.
SkyMate was recently approved for commercial fishery use in four US regions. This significant burst of activity in an already growing company suggests that SkyMate is here to stay.
Though based on very different technologies, both SkyMate and the Pactor/SSB systems offer similar pricing, and similar functionality. SkyMate would be a good choice for a beginning computer user or technophobe, while the Pactor solution is ideal for ham radio users or those who enjoy getting a little hands-on with technology. Both have proven to be reliable and cost-effective means for getting email at sea.
Pactor and Pactor Modems
Going to Sea and Staying in Touch
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