Thanks for the questions. I'll try my best to respond:
Sorry, but I cannot give you specific instances of where satphones have failed in disasters. Perhaps others with access to that data, can give examples. But based on my (limited) personal experience, numerous reports from yacht and commercial
small-craft owners (eg: live aboard dive and surf charter
and gas survey
vessels) using the phones, information from people in the communication industry regarding technical and operational aspects which explain what users have described, and the actions of informed decision makers selecting communication systems for particular applications, I conclude the drop out rate in equatorial areas must be significant. I'm told the Thuraya satellite
phones are less problematic; but this service
of geostationary satellites at higher altitude covers a limited area of the world.
From personal experience, I am aware that on land, satphones have difficulty in valleys and under vegetation because the satellites are a long way above and/or low to the hirizon, the signal strength is weak, portable antennas are rather ineffective (relative to an aimed dish) and almost any material can block the signal. In SE Asia
, satphones lose signal under heavy cloud, on land and sea; even the satellite
here drops out - despite roof top dish antennas - when heavy clouds roll in.
Satphone users have remarked to me that their satphone is more reliable in temperate latitudes, but less reliable in lower latitudes. Others might be able to corobberate or refute.
I don't have market statistics to demonstrate HF use, but I can tell you what I see:
The two main HF radio
makers in Australia
have expanded many times over in the last ten years. I was in the new office/factory/wharehouse of one in Perth just six months ago. The other has gone international, establishing offices in Europe
and North America. Even ICOM
has created a commercial HF radio
- the F7000 - to get into the expanding commercial market for HF radio
Many of these commercial HF/SSB radios have smart linking systems, so a network of radios routinely do test calls to each other using digital signalling, so when a user wants to talk to a particular radio in their network their radio already knows which frequency to call on to get the best available comms. So there is a lot less unsuccessful or difficult voice calling activity on the frequencies.
It's true that most marine Coast Stations around the world closed following the implementation of GMDSS, when large commercial vessels were forced to carry high power satellite systems and therefore transferred their phone
traffic to it. Their broadcast weather
forecasts, along with potition reporting and telephone traffic stopped. At the same time, email
transfer of the same information from isolated users - via both satellite and HF/SSB radio has increased substantially, so a lot of voice communication on HF marine and land frequencies has transferred to the data frequencies.
If you consider only the weather
information available via SailMail (or the HAM WinLink service) eg: METAREA forecasts, GRIB weather charts
, coastal weather forecasts, Typhoon2000 warnings/reports (in this region) - it's understandable that there are fewer voice broadcasts of such information. Gathering such information via data transmission
over HF/SSB radio is a lot more convenient (the Pactor modem
and the software
do any say again stuff while you are relaxing with a sundowner or busy changing sails) and this free information (eg: GRIB weather charts) can be in a more useful graphical form to display overlayed on electronic navigation
displays; and it has future predictions for passage
planning. It's a quantum leap ahead of listening to voice broadcasts.
Other services on marine HF/SSB have also changed from voice to digital signalling via low-cost services such as SailMail and WinLink. For example, position reports are now sent as an email
to be available for family
and friends to see, displayed on the web, with a short comment. So there is no need for Coast Stations to take reports verbally. And a telephone interconnect to update family
and friends of your cruise
is replaced by an email post to a blog site, or a MailMerge style email to hundreds of people on an e-mailing list.
Other advantages to recreational marine users of these changes is that whereas in the past it was difficult to find a voice frequency free off high powered transmissions from base stations running phone
interconnect links, or broadcasting the weather, or taking postion reports etc, now it is not. There are now lots of available HF/SSB voice frequencies and plenty of air time available for us low-budget little people to conduct our own voice skeds and voice comms with other cruisers. It's common for groups of cruising friends to establish regular sked times to make voice contact, share info, advises about cheap
shore deals on fuel
etc, and report progress or hazards seen at sea; like semi submerged containers. And if you miss the sked because of a squall or sleeping in at an anchorage, you can send them all an email later.
Speaking more generally about availability of published information related to where systems such as satellite comms have faults, my experience is that people and organisations generally don't highlight such information. For example, in my field I've provided safety reviews
, operating procedures etc; commonly after incidents involving death or serious injury. In many cases it appears that people and organisations do not wish to admit their existing systems were flawed, as it might imply incompetence or expose them to legal
issues. In some instances it's been hard for me to get the recipient organisation which requested the report to even verbally acknowledge they have the recommendations; certainly not in writing. Some don't want to speak on the phone. (The Law really is an ass.) So what I've learnt is to watch what they do subsequently. In most instances the report recommendations become strictly applied operating practices; but without ever admitting to the change. Applying that strategy to the satellite/HF radio queston I can report from my experience that:
1. Following the 9/11 disaster and the New Orleans
Tropical Storm disaster, a public access natural disaster email system has been established in the USA. It uses HF/SSB radio email, not satellite email. It was created by and is managed by the USA's Amateur Radio community. My experience is that HAM's know a lot about satellite communication systems too.
2. Following the 2010 fires in Victoria (Australia) that killed a few hundred people, the Country Fire Authority has implemented an alternate communication system to the existing trunked radio, mobile phone and FM radio warning and command/control system that depended on hilltop communication towers. These stopped working during the fire emergency
because of a lack of electricity, and took eight days to repair to get just some basic comms working for Police, fire and emergency
services. The CFA is now installing HF/SSB radios and Pactor
modems in fire trucks, fire stations etc, for voice, email, sms and position reporting. They chose a HF/SSB radio based system ahead of satellite phone
based system. That has to say something significant, especially since they have (politically driven) access to ample money
in the wake of the disaster, which was exacerbated by the failure of the existing hilltop tower based communication systems during the event.
3. In the marine safety network situation, we know that marine authorities choose HF/SSB radio over satellite comms. I think it's reasonable to assume a lot of smart and experienced mariners and communications
professionals were involved in reaching that conclusion. In my experience, officers in national communications
authorities are almost always HAMs too. Their knowledge and experience from HAM activity goes into decisions about appropriate communication systems and technical specifications for specific functional needs; like marine comms and marine emergency comms.
In each of these examples, we have competent and responsible people with a genuine personal interest in effective communications, choosing HF/SSB radio ahead of satellite comms. Regardless of a lack of personal access to satellite handphone drop-out statistics, there has to be a message in these decisions.
In terms of operating my yacht, I see that both systems have a place. We are lucky to have the advantage of choosing to use the appropriate service for the particular circumstances; given all considerations. For the tender ride ashore, or if stepping up into the liferaft
, a waterproof bag with satphone and VHF
marine radio along with plenty of batteries is the only practical option; despite any limitations. But on-board, the marine HF/SSB radio is way ahead because of the much lower cost of voice calls or emails and the fact it links into the established marine safety/emergency communications service and all the professional expertise and rescue
capability of commercial vessels.
Happy cruising for all.