Hi Dave and others,
I'm beginning to feel like you're responses are aimed at pulling another chapter out of me! At the risk of appearing bloodyminded:
I'm aware of the AMVAR system, but I understand it is not compulsory, and is in a testing phase at present, and is currently used on a limited number of big ships only. Maybe I have got this wrong? My guestimate is therefore that for yachts cruising close to major shipping
lanes, this could be useful. Anywhere else, it will be necessary to rely on some smaller boats - without AMVAR - to be listening for the MRCC DSC alarm
call to assist you.
I expect there is a lot of deliberate disinformation around regarding the complexity of marine
; especially from the mouths of satellite phone
salesmen/women. I saw the photos from Cat Man Do. I started with Codans not too dissimilar to the photo
. The modern photo
is a HAM radio, designed for radio enthusiasts who are keen to experiment
with HF/SSB radio. A moden marine
HF/SSB radio is much simpler, has BIG lettering so most people can see the display without reading glasses, has a lot of smart electronics
, does a lot more than the old Codan, but is far more straightforward to operate than the very versatile HAM radio. For example, do a search for ICOM's M801E or M802
Here is what SailMail says about using HAM radios for marine comms:
"The Icom IC-718 and most other ham radios work with SailMail if they are equipped with a High Stability Crystal Unit, and if the radio is modified to transmit on all bands. .... Ham radios are not type accepted for use on marine frequencies and their use may not be permitted by your country's radio regulations. For US-registered vessels, the US FCC requires marine type-accepted radios (e.g. Icom M802, M710, M700Pro etc).
There is another reason why it is a bad idea to use a Ham radio... Ham radios are much more complicated to operate than marine radios because they have many features that marine radios don't need. If these options and features are set incorrectly the radio will not work. Often on a cruising boat there is only one knowledgeable HAM on-board. If that person is injured and others need to use the SSB, they will be much less likely to be able to operate a HAM radio than they would a marine radio. Note that it is perfectly legal to use Marine radios such as the Icom M802 on Ham frequencies. This is a better approach."
The people who started SailMail are HAMs; so they should know.
One reason for DSC
in marine HF/SSB radios is to reduce an aspect of uncertaintly with any radio comms; "have I called on the right frequency/channel and is the intended recipient's radio turned on?" Each radio has an MMSI number and this is akin to a phone
number. Yachts can call each other using the number. The radio speaker in the recipient's radio is normally muted - on DSC watch - but the radio can be scanning for a call that has it's MMSI number. If detected, the speaker mute opens, and the radio goes into an alarm/ring state. There is also a revertive tone sent back to the caller. As the caller, if you hear the tone you know you made contact with the desired radio. If you do not, then try a different frequency.
This process of calling by tones - and listening for the revertive tone to confirm you reached the desired radio - is similar to SelCall in commercial
HF/SSB radios. My HAM friend who introduced me to HF radio
about 35 years ago told me to get that feature in a straight forward commercial
HF/SSB radio, to avoid all the background noise
associated with maintaining a listening watch for calls on HAM radios, or commercial or marine HF/SSB without Sellcall or DSC. That's what DSC does for you in the marine HF/SSB radio. The radio can monitor
or private calls, and there is no noise
from the speaker.
I'm sure the VOR boats have a great satellite
system. If I recall
correctly from the previous race
, the huge dish that must be aimed at the satellite
occupies most of the space forward of the mast
, down below. Those boats need broadband internet
so they can send video etc for the benefit of sponsors, TV news etc. But I'd be very surprised if the VOR boats don't also have a modern marine HF/SSB radio with DSC.
According to a UK contact who sells marine HF/SSB radios and runs radio training courses, "On both rallies (ARC annd Oyster) all yachts must have an SSB and email
and some are opting for both satellite and SSB for the email
." Marine HF/SSB radios with email capability (ie: SailMail) will provide everyone with low-cost but reliable communication and keep everyone informed of rally operations, next port arrngements etc.
When rallies operate around SE Asia
- some have over 100 boats - it is really frustrating for the organisers and other participants when yachts do not have a marine HF/SSB radio. It means they cannot receive information directly from organisers at skeds, they cannot send daily position reports, and they cannot take part in skeds when yachts share information. But rally participants are not willing to pay higher fees
to the orgnaisers so they have the money
to employ a bunch of staff to make thousands of satellite phone
calls to yachts with only satellite phones and marine VHF radios. Consequently, a number of boats with marine HF/SSB must volunteer to be relay boats. They collect position reports from boatws without marine HF/SSB radios - normally via VHF - and forward to organisers via their marine HF/SSB. In the other direction, they must record info from the organisers during the HF/SSB sked, then pass it on via VHF. Apart from the effort and responsibility, these techniques regularly produce incorrect information, which can sometimes create significant consternation and problems; exacerbated because the boats without the HF/SSB radio cannot communicate direct to the organisers, by voice or through email. It's a real pain in the butt for organisers and those participants who have made the effort to properly equip their yacht.
Returning to the percieved complexity of setting up and operating a marine HF/SSB radio:
1. DSC is desgned to make operation easier, and to make it easy to maintian a 24/7 watch for distress
calls from other vessels with DSC equipped marine HF/SSB radios, or from MRCCs looking for a vessel to help someone nearby.
2. In combination with email on-board - eg low-cost SailMail (or Winlink for HAMs) - the marine HF/SSB radio makes life on-board simpler and safer. Weather
information, TS warnings, ordering parts
to be sent to the next stop, booking marina berths and chasing up the house rent that is funding
your trip, sending position reports, updating a blog etc are so much easier. And in this region, you can spend more time away from marinas, wi-fi and internet
cafes, in beautiful locations where the cost of living is much cheaper. You easily get back the money invested in a marine HF/SSB and Pactor modem
3. The KISS-USB counterpoise
is a recent development that does the job of an earth connected to the Automatic Antenna Tuner (ATU). See www.kiss-ssb.com
According to my (sceptical of new gismos) HAM friend who recently retired and closed his business supplying marine and aircraft radios "I can see what they are doing, using a multi wire, multi frequency "Counterpoise" as half a dipole, with the tuner adjusting the overall counterpoise
and back stay or whip to resonance. A novel approach that might just work". (Yep, HAM nurd stuff that's a bit beyond me too, but it does comfirm that from his sceptical techo perspective, this is a workable solution. Others might like to comment.) This KISS-USB counterpoise removes the need to have an external earth plate or to lay copper foil in the boat. Installation
will be faster and cheaper.
4. When installing a marine HF/SSB radio with DSC it usually (eg: for the ICOM M802 or M801E) requires a seperate DSC receive antenna. As confirmed by my HAM friend, this can be the AM/FM radio antenna (receiving only - but not an antenna that involves transmission
, such as the AIS
or VHF radio antenna) passed through a splitter box to feed both the stereo and the HF/SSB radio. Simple, cheap
and quick. No need to find space for another (expensive) whip antenna.
When evaluating the seductive, instant gratification and apparently so simple comms solution offered by the satellite phone
salesman, the prudent sailor might recall
that experienced rally organisers (eg: ARC, & Oyster) require a marine HF/SSB radio and email; not a satellite phone. And that:
1. The satphone salesman or women gets a commission on the satellite phone sale
and the call time you buy. A similar financial reward arrangement that worked very successfully to sell the sub-prime loans and other financial scams which precipitated sinking the world economy. It's hard to overcome human nature.
2. He or she will not be out there on the water
trying to solve your problems.
3. But the professional mariner, search and rescue
helicopter pilot, Coast Guard skipper
. MRCC operator and others who helped develop the marine HF/SSB DSC system as a workable solution - and who do not benefit from your satphone or subsequent call time purchases - will be out there too. They'll be putting their lives at risk to help you. Help them by fitting the comms equipment
"While satellites and satellite-compatible distress beacons have significantly improved the effectiveness of SAR operations, the system is NOT a substitute for carrying appropriate marine or aviation radio.
Depending on the circumstances, your initial distress alert should still be made by radio if possible. You should activate your distress beacon only if contact cannot be made by any other means or when told to do so by a rescue authority. "
"Dedicated SAR facilities are limited in Australia. When necessary, other facilities are diverted from their primary function by arrangement or request."
(from the AMSA website)
The satphone has it's useful roles - private calls to solve a shore problem so you can remain in that beautiful anchorage, in the tender
or canoe, and the unlikely event of stepping up into a liferaft
- but it cannot, at any stretch of the satphone salesman's imagination, replace the marine HF/SSB radio with DSC.