24/11/2008 | by Oceangybe
Words by: Hugh
In an effort to turn this into a bit of a two way flow of information, I’m going to start by posting answers to a few of the common questions we hear from folks about the trip. Things like “What do you eat?” “How do you update your website [infrequently] from the middle of the ocean?” “Do you sleep at night? Or sail” And please feel free to fire us off an email if you have any other questions at all about the trip. See the Contact page for our addresses.
Often we’re asked what sort of technology we have aboard. And by technology, I mean modern technology. The sails and compass are invaluable, but what do we have a board that you might not expect? Like a printer/scanner. Lets break it down into categories of Communication, Navigation, Documentation and Safety. In this installment I’ll talk a bit about the technology we have aboard for communication.
As you already know, our laptop computer is one of the most important pieces of technology we have aboard. Not too surprising really, but it fits into all the categories above; serving as the hub for all the periphery devices. However, its two primary functions are receiving weather information and emails over the HF radio, and running our charting program, CMAP, which combined the GPS give us our position on the globe and in relation to any reefs and other navigational hazards (like sirens, for instance).
But before we get into the complicated stuff with the computer, lets start with basic communication. Most importantly is the VHF (Very High Frequency) radio. Most every boat is equipped with one of these. For short-range communication, less than 25 miles, it is the standard. When arriving at a new port we call customs and immigration on the VHF radio, when a large tanker ship passes close to us, we hail them on channel 16 to ask them to kindly not run over us. Once the ‘transmit’ button of our VHF radio jammed “ON”. The next day we learned from another cruising boat that we had been broadcasting the conversations from our cockpit to all the surrounding boats for the whole evening. Oops.
Now 25 miles isn’t that far. Our link to a world farther a field is our HF (High Frequency) or HAM radio. We use the HF radio to get weather information, send and receive emails, and speak to other boats as well as people ashore. So the first function is speaking with other boats and shore stations. On our way down to New Zealand we spoke to Ron Kolody in Vancouver and Peter Dei in California, over 6000km’s away. At the moment as we sail towards South Africa we speak with 2 land-base HAM radio operators in that country daily, as well as a number of other boats making the same passage.
Along with voice, the HF radio can also transmit data, aka email. Email using an HF radio? Yup! Pretty nifty, huh? Simply type a text email on the laptop, and our handy modem converts it to squeaks and squelches, similar to those noises that come out of a fax machine (once referred to as the urban mating call). The radio broadcasts these to a land-based radio station, which relays the emails to the in-ter-web and the intended recipients email addresses. Broadcasting data over radio waves in this manner is slow and can be temperamental; it can depend on the time of day, the distance to the shore station, ionospheric conditions (you’ll have to look that one up on your own) and even solar flares. But mostly it works.
Not only does email let us communicate with folks back home on a daily basis, we also send out blogs and get weather information via email. Blogs? With the invaluable and tireless help of Thea Robertson and Jess Sprowson, our website gets updated even while we’re in the middle of an ocean. After typing our missives on the laptop (which hopefully hasn’t been taken out by a wave or black magic) we send them off to Thea and Jess via email, over our HF radio (see above). These two faithfully upload our often longwinded ramblings to oceangybe.com for you read. Simple as that.
And weather: also over email. To get wind and weather predictions, the tool we most often consult is called a GRIB file, which again we receive over email. A GRIB is a computer-generated prediction of weather conditions that can be received over email. We send an email request to an automated (and free) service, asking for wind, wave and pressure conditions in our area of the ocean for a given time period, say, the next 72 hours. Moments later we receive an email with that information we requested. This is presented in a nice, easy to read overlay on a map of our area. It can be less accurate than a weather forecast made by an actual meteorologist, but is very valuable none-the-less.
The other common weather forecast we receive over the HF radio is a weather fax. This is a more traditional synoptic chart, vetted by a meteorologist. To receive these, we simply tune our radio and modem to a given frequency at a certain time of day, and a nifty program on the laptop decodes the urban mating call. Displayed is a map of high pressures, low pressures and frontal systems.
So there you have it, communication = radio’s and laptops.